.mono/config

@@ -0,0 +1,2 @@
+[project]
+name = "code-analysis"

.mono/refs/HEAD

@@ -0,0 +1 @@
+c813292f1400c21462beea82e2f3bcb5a3b7cc8dc8ca26010cd530d6f9166658

PROJECT_GROUNDING.md

@@ -1,392 +0,0 @@
-# cstat Grounding Plan
-
-## 1. Project Intent
-
-`cstat` is a Rust codebase-shape analysis tool. It exists to make messy Rust codebases easier to inspect, reason about, and improve in bounded steps.
-
-The project should prove three linked ideas:
-
-1. **Codebase shape exploration** — existing probes expose different structural views of a Rust codebase.
-2. **Verified complexity function** — those probes can feed a deterministic, explainable complexity/cleanup function.
-3. **RLVF harness / environment** — the tool can support baseline, attempted cleanup, verification, re-measurement, and structured feedback for human or agent-driven codebase fixing.
-
-This project is not trying to become a general-purpose static analyzer, automatic refactoring engine, full RL training system, architecture platform, or web product.
-
-## 2. End-State Goals
-
-### 2.1 Codebase Shape Exploration
-
-`cstat` should let a user explore the shape of a Rust codebase through multiple static lenses. Existing probes are valuable because each one describes a different part of codebase shape.
-
-Relevant shape views include:
-
-- line/file size and distribution;
-- symbol counts and concentration;
-- module dependencies and coupling;
-- per-function and per-file complexity;
-- static dead-code candidates;
-- static test/benchmark reachability;
-- call-flow or call-trace views where useful;
-- coverage or cluster views where they directly support exploration or verification.
-
-The goal is not to hide these probes. The goal is to make clear why they exist, when to use them, and how they contribute to the larger project purpose.
-
-### 2.2 Verified Complexity Function
-
-`cstat` should define one deterministic complexity or cleanup function derived from existing metrics.
-
-This function should be:
-
-- deterministic for the same input codebase;
-- explainable from its component metrics;
-- stable enough to consume from JSON output;
-- tested against fixtures and invariants;
-- honest about what it measures.
-
-“Verified” does not mean the function proves true code quality. It means the function has a stated contract, stable inputs and outputs, and tests showing that obvious structural changes move the score in expected directions.
-
-Example invariants:
-
-- adding branches should not reduce the complexity component;
-- adding large functions should not improve the size/complexity result;
-- adding unnecessary dependencies should not improve coupling;
-- reducing test reachability should not improve the verification signal;
-- preserving behavior while lowering measured complexity should improve the cleanup signal.
-
-### 2.3 RLVF Harness / Environment
-
-`cstat` should support an RLVF-style loop for codebase-fixing attempts.
-
-The minimal loop is:
-
-1. establish a baseline shape/complexity measurement;
-2. allow a human or agent to make a bounded cleanup attempt;
-3. run the project’s verification command, such as tests or build;
-4. re-measure shape and complexity;
-5. emit structured feedback describing whether the attempt improved the measured objective while preserving required behavior.
-
-The harness does not need to train a model. It does not need to call an LLM. It does not need to apply patches automatically. For this project, the harness is the environment and feedback mechanism around a codebase-changing attempt.
-
-## 3. Boundaries / Non-Goals
-
-The MVP stays bounded by these rules:
-
-- Rust-only for now.
-- Static-first analysis.
-- Existing probes should be organized before new probes are added.
-- New analysis is only in scope if it directly supports shape exploration, the complexity function, or the RLVF harness.
-- No automatic refactoring.
-- No RL training loop.
-- No LLM integration.
-- No promise of perfect macro expansion, dynamic dispatch resolution, or runtime truth.
-- No web UI.
-- No plugin system.
-- No multi-language support.
-- No broad benchmark suite before the core loop works.
-- No feature is justified merely because it is interesting.
-
-A change is in scope only if it improves one of these:
-
-- codebase shape exploration;
-- the verified complexity function;
-- the RLVF harness/environment;
-- the demo proving those concepts;
-- the documentation needed to make the project understandable.
-
-## 4. Current Assets
-
-The project already has substantial useful material:
-
-- multiple CLI probes for structural codebase analysis;
-- focused root commands for each maintained analysis path;
-- JSON output modes;
-- tests around several CLI behaviors;
-- static analysis modules for size, symbols, dependencies, complexity, dead-code candidates, reachability, call flow, coverage, clustering, and related views;
-- `cstat-agent-use.md`, which already points toward agent-oriented tool use;
-- enough real code for dogfooding the tool on itself.
-
-These assets should be treated as the foundation, not as clutter to discard by default.
-
-## 5. Current Gaps
-
-The missing pieces are mostly framing, contracts, and end-to-end proof.
-
-### 5.1 Purpose and CLI Organization
-
-The CLI exposes many capabilities, but the project purpose is not yet clearly organized around shape exploration, complexity scoring, and RLVF feedback.
-
-The probes work, but they need to be presented as intentional views of codebase shape rather than as unrelated commands.
-
-### 5.2 Verified Complexity Function
-
-The project does not yet define a single named complexity/cleanup function with:
-
-- explicit metric inputs;
-- a deterministic formula;
-- a stable JSON output shape;
-- stated invariants;
-- tests proving those invariants.
-
-### 5.3 RLVF Harness Flow
-
-The project does not yet demonstrate the full loop:
-
-- baseline measurement;
-- bounded cleanup attempt;
-- project verification;
-- after measurement;
-- structured feedback/reward evidence.
-
-Without this loop, the RLVF claim is only conceptual.
-
-### 5.4 Demo
-
-The project needs a concrete demo showing that the tool works end to end.
-
-The demo should show:
-
-- human exploration of a messy codebase;
-- machine-readable output suitable for an agent;
-- a before/after verification path;
-- how the complexity function changes after a bounded cleanup.
-
-### 5.5 Public Explanation
-
-The README is too thin to communicate what the project is, why it exists, or how the existing pieces fit together.
-
-The project needs enough surface-level polish that another developer can understand:
-
-- what problem `cstat` solves;
-- what commands or profiles to start with;
-- what the metrics mean;
-- what the limitations are;
-- how the demo proves the core claims.
-
-## 6. Gap-Fill Plan
-
-### 6.1 Organize Existing Probes
-
-Document the existing probes as codebase-shape views.
-
-For each probe, clarify:
-
-- what shape dimension it exposes;
-- whether it is mainly useful for humans, agents, RLVF feedback, or all three;
-- what command produces it;
-- whether the output is stable enough for machine use.
-
-This should make the existing breadth feel intentional without requiring every probe to become part of the core proof.
-
-### 6.2 Define Tool-Use Profiles
-
-Define limited profiles that combine existing probes for specific workflows.
-
-Candidate profiles:
-
-- **human exploration profile** — emphasizes readable summaries and cleanup starting points;
-- **agent steering profile** — emphasizes compact JSON, hotspots, constraints, and suggested drilldowns;
-- **RLVF profile** — emits stable fields needed for before/after feedback and reward calculation.
-
-Profiles should be thin orchestration over existing analysis where possible.
-
-### 6.3 Add the Complexity Function
-
-Define a named complexity or cleanup cost function.
-
-The implementation should reuse existing metrics first. The first version should prioritize determinism, explainability, and tests over sophistication.
-
-The output should include:
-
-- score or cost value;
-- score version;
-- component breakdown;
-- top contributors/hotspots;
-- enough metadata to compare before/after results.
-
-### 6.4 Verify the Complexity Function
-
-Add tests that prove the function’s contract.
-
-The tests should focus on observable properties, not incidental implementation details.
-
-Useful test cases include:
-
-- a small/simple fixture has lower cost than a deliberately messy fixture;
-- adding control-flow branches increases or preserves complexity cost;
-- adding dead private functions worsens the relevant component;
-- reducing test reachability does not improve the RLVF signal;
-- JSON output contains the expected stable fields.
-
-### 6.5 Build the RLVF Harness Flow
-
-Create the minimal harness path for codebase-fixing attempts.
-
-The harness should produce an artifact that records:
-
-- task or attempt metadata;
-- baseline profile output;
-- verification command and result;
-- after profile output;
-- complexity delta;
-- feedback/reward signal;
-- reasons for acceptance or rejection.
-
-The harness should remain separate from model training or patch generation.
-
-### 6.6 Add an End-to-End Demo
-
-The demo should prove the project’s core claims without becoming a second product.
-
-A good demo path is dogfooding `cstat` on itself:
-
-1. run shape exploration on the current repo;
-2. identify an obvious cleanup target from the output;
-3. make or describe a bounded cleanup attempt;
-4. run project verification;
-5. re-run the relevant profile;
-6. show the feedback artifact.
-
-If dogfooding is too noisy, add a small fixture crate that intentionally contains a few simple forms of messiness.
-
-### 6.7 Polish Public Explanation
-
-Update the public explanation after the core loop exists.
-
-The README should explain:
-
-- the three project goals;
-- the basic commands or profiles;
-- one short demo;
-- what the metrics do and do not mean;
-- how humans and agents use the tool differently;
-- the non-goals that keep the project bounded.
-
-## 7. Completion Criteria
-
-The MVP is complete when all of the following are true:
-
-- The project can be explained in one paragraph.
-- Existing probes are framed as codebase-shape views.
-- A deterministic complexity function exists.
-- The complexity function has stated inputs, output, and invariants.
-- Tests verify the complexity function’s basic contract.
-- An RLVF-style harness flow exists.
-- The harness produces structured feedback for a before/after cleanup attempt.
-- A demo shows shape exploration, complexity scoring, verification, and feedback.
-- The README explains the project clearly enough for a new developer to try it.
-- Non-goals are documented and used to reject unrelated scope.
-
-## 8. Scope Guardrail
-
-The project should not expand just because another metric, command, or dashboard would be interesting.
-
-The guardrail is:
-
-> If a change does not support codebase shape exploration, the verified complexity function, the RLVF harness, the demo, or the public explanation of those pieces, it is outside the MVP.
-
-## 9. Current CLI Polish Pass
-
-We are currently going through the existing CLI commands and probes one by one. The goal is to polish, clarify, and prune the extant surface before designing RLVF targets or higher-level harness behavior.
-
-This pass is not about adding new analyzers. It is about deciding, for each existing command:
-
-- what codebase-shape concept it measures;
-- whether the measure is useful for humans, agents, and later RLVF workflows;
-- whether the output is granular enough;
-- whether the behavior is tested well enough;
-- whether the CLI/help/docs explain it clearly;
-- whether any parts should be renamed, folded into another concept, demoted, or dropped.
-
-Only after this CLI/probe pass is complete should we design the RLVF target or targets, because the RLVF harness needs stable, well-understood measurement primitives.
-
-## 10. Current Branch / Worktree Status
-
-- Main line now includes the accepted `loc` polish work.
-  - `loc` is a first-class line/size-shape probe.
-  - The `loc` branch/worktree was folded in and removed.
-- Main line now includes the accepted `symbols` polish work.
-  - `symbols` is a first-class symbol-shape probe.
-  - It clarifies impl/trait-impl semantics, selected-file behavior, JSON output, and symbol granularity.
-  - The `symbols` branch/worktree was folded in and removed.
-- `-complexity` branch:
-  - The old broad `complexity` command has been sharded.
-  - The sharding direction is accepted.
-  - Each new individual item still needs review before it is ready to fold in.
-  - Current stopping point: complexity concept split exists, but the resulting probes are not yet accepted as polished.
-
-## 11. Stopping Point
-
-- We resumed the CLI polish/pruning pass long enough to fold in the accepted `loc` and `symbols` work.
-- `loc` and `symbols` are now the first accepted polished probes on the main line.
-- We agreed that the old `complexity` command was too broad and vague.
-- We narrowed the intended complexity split to specific probes from the existing complexity behavior:
-  - branching/control-flow path complexity;
-  - signature/type-boundary complexity;
-  - span/function-body size.
-- We agreed not to treat all codebase complexity as one vague command.
-- Current next review point is the sharded `-complexity` worktree/branch.
-
-## 12. Next Steps
-
-1. Review the sharded `-complexity` items individually.
-2. Accept, revise, or reject each complexity shard based on whether it is granular, objective, tested, and useful for human/agent/RLVF workflows.
-3. Fold in only the accepted complexity shards.
-4. Continue the same polish/pruning review for the remaining existing CLI commands.
-5. After the measurement primitives are stable, design the RLVF target or targets around those accepted probes.
-
-## 13. Extreme Bare Minimum
-
-Before the broader MVP work, the project needs a narrow, polished, resume-linkable slice that proves `cstat` is already usable.
-
-This slice is not the full verified complexity function or RLVF harness. It is the smallest public path that shows a clean CLI and a credible human/agent demo.
-
-### 13.1 Polished CLI MVP
-
-The CLI MVP should expose a small accepted command surface rather than every existing probe.
-
-For this slice:
-
-- `loc` is folded in as an accepted line/size-shape probe;
-- `symbols` is folded in as an accepted symbol-shape probe;
-- present both as first-class codebase-shape probes;
-- make command names, help text, examples, and output modes clear enough for a new user to run without project context;
-- keep JSON output stable enough for agent consumption;
-- hide, demote, or leave out unfinished rough commands from the public happy path.
-
-The goal is a CLI that feels intentional and usable, not a complete analysis platform.
-
-### 13.2 Human Demo
-
-Add a short demo showing how a person uses the polished CLI on a Rust repo.
-
-The demo should show:
-
-- the exact commands to run;
-- how to read file/size shape output;
-- how to read symbol concentration output;
-- how those outputs point to likely cleanup targets;
-- one brief investigation or before/after walkthrough.
-
-### 13.3 AI-Agent Demo
-
-Add a short demo showing how an AI agent should consume the polished CLI.
-
-The demo should show:
-
-- the exact commands an agent should run;
-- the JSON output path or mode it should consume;
-- how to identify hotspots from structured output;
-- how to choose a bounded next probe or cleanup target from that evidence.
-
-This demo should stop at agent steering. It does not need the full RLVF harness, model training, automatic patching, or reward loop.
-
-### 13.4 Completion Criteria
-
-The extreme bare minimum is complete when:
-
-- the polished CLI path is narrow, documented, and runnable;
-- `loc` and `symbols` are folded into the main line as accepted probes;
-- rough unfinished commands are not part of the primary public path;
-- a human demo explains how to use the output;
-- an AI-agent demo explains how to consume the JSON and pick a bounded next action;
-- the README can support a resume link without implying the broader MVP is finished.

README.md

@@ -4,7 +4,6 @@ Terminal CLI tool to examine a codebase through a statistical lens
 ## helpful commands
 ```bash
 cstat --help # cli options
-cstat scorecard --path . --json # machine-readable code complexity cost
-cstat loc --path . -v # size-shape analysis plus explanations
-cstat test-reachability --path . --json # structured static test/bench reachability
+cstat -v # basic dashboard plus explanation
+cstat <any> -v # runs the command and gives an explanation of the metrics
 ```

cstat-agent-use.md

@@ -9,19 +9,28 @@ and tests preserve behavior.
 
 ## Starting point
 
-Start with the focused commands that answer the current cleanup question:
+Run the focused report first:
 
 ```sh
-cstat scorecard --json --path <project_root>
-cstat loc --json --path <project_root>
-cstat symbols --json --path <project_root>
-cstat deps --json --path <project_root>
-cstat dead-code --json --path <project_root>
-cstat test-reachability --json --path <project_root>
+cstat report --json --path <project_root>
 ```
 
-The stale `summary`, `report`, and `advanced` entry points have been removed.
-Use focused root commands directly.
+Omitting the command is equivalent to `cstat summary`, which is the same focused
+report. The JSON contains:
+
+- `line_counts`: total code lines, physical lines, and per-file counts.
+- `symbols`: total and per-file counts for functions, structs, enums, traits,
+  `trait_impls`, consts, statics, and parse-error state. `trait_impls` means
+  `impl Trait for Type` blocks only, not inherent `impl Type` blocks.
+- `dependencies`: module list, module interdependency matrix, edge count, and
+  fan-in/fan-out degrees.
+- `dead_code`: functions not statically reachable from main, tests, or
+  benchmarks.
+- `test_reachability`: static test/benchmark reachability, step counts, max
+  depth, and per-function/per-edge reaching-entry counts.
+
+The focused report intentionally excludes older exploratory dashboards. They
+remain available under `cstat advanced ...`.
 
 ## Focused drilldowns
 
@@ -39,16 +48,28 @@ Each accepts `--json` for structured output.
 - `cstat dead-code --json --path .` — static cold-function candidates.
 - `cstat test-reachability --json --path .` — static test/benchmark
   reachability and reaching-entry counts.
-- `cstat branching --json --path .` — per-function decision/path complexity.
-- `cstat signature --json --path .` — per-function API boundary complexity.
-- `cstat span --json --path .` — per-function implementation span metrics.
-- `cstat scorecard --json --path .` — deterministic structural complexity cost
-  for agent optimization, with component costs, scope breakdown, and hotspots.
+- `cstat complexity --json --path .` — per-function cyclomatic, cognitive,
+  nesting, parameter, and line metrics.
 
+## Advanced / legacy commands
+
+Use these only when the focused report points to a question they answer:
+
+- `cstat advanced summary --json --path .` — previous broad dashboard.
+- `cstat advanced flow --json --path .` — raw static call graph.
+- `cstat advanced graph --json --path .` — graph centrality, SCCs, PageRank.
+- `cstat advanced flow-heatmap --json --path .` — previous random-walk heatmap.
+- `cstat advanced circuits --json --path .` — call-graph community detection.
+- `cstat advanced redundancy --json --path .` — similar/duplicate function
+  candidates.
+- `cstat advanced dist --json --path .` — metric histograms/correlation views.
+- `cstat advanced map --json --path .` — terminal architecture map.
+- `cstat advanced dump --path .` — previous diagnostic-score dump.
+- `cstat advanced guide <topic>` — metric reference material.
 
 ## Cleanup workflow
 
-1. Run the focused `cstat` commands that match the cleanup target.
+1. Run `cstat report --json --path .`.
 2. Read the focused sections in this order:
    - line counts: find oversized files first;
    - symbols: find files with too many definitions;
@@ -56,8 +77,8 @@ Each accepts `--json` for structured output.
    - dead code: review cold candidates before deleting;
    - test reachability: compare code surface against what tests/benches can statically reach.
 3. Plan one cleanup stage at a time.
-4. After each stage, rerun the same focused `cstat` commands and the project's
-   own build/tests. cstat metrics do not prove correctness.
+4. After each stage, rerun `cstat report --json --path .` and the project's own
+   build/tests. cstat metrics do not prove correctness.
 
 ## Safety rules
 

src/ast_parser.rs

@@ -481,6 +481,11 @@ fn type_complexity(ty: &Type) -> usize {
     }
 }
 
+/// Convert a Type to a readable string (public wrapper for cross-module use).
+pub fn type_to_string_pub(ty: &Type) -> String {
+    type_to_string(ty)
+}
+
 /// Convert a Type to a readable string.
 fn type_to_string(ty: &Type) -> String {
     match ty {

src/call_trace.rs

@@ -762,16 +762,14 @@ fn render_entry_listing(listing: &EntryListing) {
 
 fn render_human(output: &CallTraceJson, verbose: bool) {
     println!("cstat call trace");
-    println!("static possible-call expansion; not a runtime execution trace");
     if verbose {
         render::verbose_block(&[
-            "Built from cstat's Rust source call graph.",
-            "Branches are not evaluated; every statically resolved callee is shown.",
+            "Static call graph rendered from one selected root.",
             "Cycles stop expansion; shared functions expand in each stack.",
         ]);
     }
 
-    println!("resolved entry:");
+    println!("resolved:");
     match output.resolved.source {
         EntrySource::CargoRun => {
             println!("  cargo command: cargo run --");
@@ -803,22 +801,19 @@ fn render_human(output: &CallTraceJson, verbose: bool) {
         }
     }
 
-    println!("static expansion summary:");
+    println!();
+    render_trace_node(&output.tree);
+    println!();
+    println!("summary:");
     println!("  functions reached: {}", output.functions_reached);
     println!("  max depth: {}", output.max_depth);
-
-    println!();
-    println!("tree:");
-    render_trace_node(&output.tree);
 }
 
 fn render_file_call_trace_report(report: &FileCallTraceReport, verbose: bool) {
     println!("cstat file call trace ({})", report.file);
-    println!("static possible-call expansion per non-test function; not runtime execution traces");
     if verbose {
         render::verbose_block(&[
-            "Built from cstat's Rust source call graph.",
-            "Branches are not evaluated; every statically resolved callee is shown.",
+            "Static call graph rendered for every non-test function in the selected file.",
             "Cycles stop expansion; shared functions expand in each stack.",
         ]);
     }

src/circuits.rs

@@ -0,0 +1,687 @@
+use colored::Colorize;
+use serde::Serialize;
+use std::collections::{HashMap, HashSet};
+use std::path::{Path, PathBuf};
+
+use crate::flow;
+use crate::render;
+
+// ── Label Propagation Community Detection ────────────────────────
+
+/// Detect communities in the call graph using label propagation.
+/// Each function gets a label (initially its own index). Iteratively,
+/// each node adopts the most frequent label among its neighbors.
+
+/// Collect label frequency counts from a node's neighbors in both directions.
+/// Returns a map of label -> occurrence count across all adjacent nodes.
+fn collect_neighbor_labels(
+    node: &str,
+    adj: &HashMap<String, Vec<String>>,
+    rev_adj: &HashMap<String, Vec<String>>,
+    node_idx: &HashMap<&str, usize>,
+    labels: &[usize],
+) -> HashMap<usize, usize> {
+    let mut label_counts: HashMap<usize, usize> = HashMap::new();
+
+    if let Some(succs) = adj.get(node) {
+        for s in succs {
+            if let Some(&idx) = node_idx.get(s.as_str()) {
+                *label_counts.entry(labels[idx]).or_insert(0) += 1;
+            }
+        }
+    }
+    if let Some(preds) = rev_adj.get(node) {
+        for p in preds {
+            if let Some(&idx) = node_idx.get(p.as_str()) {
+                *label_counts.entry(labels[idx]).or_insert(0) += 1;
+            }
+        }
+    }
+
+    label_counts
+}
+
+/// Detect communities in the call graph using label propagation.
+/// Each function gets a label (initially its own index). Iteratively,
+/// each node adopts the most frequent label among its neighbors.
+/// Converges when labels stabilize.
+fn label_propagation(
+    nodes: &[String],
+    adj: &HashMap<String, Vec<String>>,
+    rev_adj: &HashMap<String, Vec<String>>,
+) -> Vec<Vec<String>> {
+    let n = nodes.len();
+    if n == 0 {
+        return vec![];
+    }
+
+    let node_idx: HashMap<&str, usize> = nodes
+        .iter()
+        .enumerate()
+        .map(|(i, n)| (n.as_str(), i))
+        .collect();
+    let mut labels: Vec<usize> = (0..n).collect();
+
+    // Create a deterministic node ordering for iteration (sorted by name)
+    let mut order: Vec<usize> = (0..n).collect();
+    order.sort_by(|a, b| nodes[*a].cmp(&nodes[*b]));
+
+    // Iterate until convergence or max iterations
+    let max_iter = 50;
+    for _ in 0..max_iter {
+        let mut changed = false;
+
+        for &i in &order {
+            let label_counts = collect_neighbor_labels(&nodes[i], adj, rev_adj, &node_idx, &labels);
+
+            if label_counts.is_empty() {
+                continue;
+            }
+
+            // Pick the most frequent label; break ties by smallest label for determinism
+            let max_count = *label_counts.values().max().unwrap();
+            let best_label = label_counts
+                .iter()
+                .filter(|(_, &c)| c == max_count)
+                .map(|(&l, _)| l)
+                .min()
+                .unwrap();
+
+            if best_label != labels[i] {
+                labels[i] = best_label;
+                changed = true;
+            }
+        }
+
+        if !changed {
+            break;
+        }
+    }
+
+    // Group nodes by label
+    let mut communities: HashMap<usize, Vec<String>> = HashMap::new();
+    for (i, label) in labels.iter().enumerate() {
+        communities
+            .entry(*label)
+            .or_default()
+            .push(nodes[i].clone());
+    }
+
+    let mut result: Vec<Vec<String>> = communities.into_values().collect();
+    // Sort communities by size (largest first), then by first member name for stability
+    result.sort_by(|a, b| b.len().cmp(&a.len()).then(a[0].cmp(&b[0])));
+    result
+}
+
+// ── Circuit Analysis ─────────────────────────────────────────────
+
+struct Circuit {
+    members: Vec<String>,
+    boundary_fns: Vec<String>, // called from outside the circuit
+    internal_edges: usize,
+    cohesion: f64,
+}
+
+struct CircuitAnalysis {
+    circuits: Vec<Circuit>,
+    inter_circuit_edges: Vec<(usize, usize, usize)>, // (from_circuit, to_circuit, weight)
+    modularity: f64,
+}
+
+/// Compute modularity Q for a given partition.
+/// Q = (1/m) * Σ_ij [A_ij - (k_out_i * k_in_j / m)] * δ(c_i, c_j)
+/// where m = total edges, k_out/k_in = degrees, δ = same community
+fn compute_modularity(
+    nodes: &[String],
+    adj: &HashMap<String, Vec<String>>,
+    partition: &HashMap<String, usize>, // node -> circuit index
+) -> f64 {
+    let m: usize = adj.values().map(|v| v.len()).sum();
+    if m == 0 {
+        return 0.0;
+    }
+
+    let mut out_deg: HashMap<&str, usize> = HashMap::new();
+    let mut in_deg: HashMap<&str, usize> = HashMap::new();
+    for n in nodes {
+        out_deg.insert(n.as_str(), 0);
+        in_deg.insert(n.as_str(), 0);
+    }
+    for (from, tos) in adj {
+        *out_deg.entry(from.as_str()).or_insert(0) += tos.len();
+        for to in tos {
+            *in_deg.entry(to.as_str()).or_insert(0) += 1;
+        }
+    }
+
+    let m_f = m as f64;
+    let mut q = 0.0;
+
+    for (from, tos) in adj {
+        let c_from = match partition.get(from.as_str()) {
+            Some(&c) => c,
+            None => continue,
+        };
+        for to in tos {
+            let c_to = match partition.get(to.as_str()) {
+                Some(&c) => c,
+                None => continue,
+            };
+            if c_from == c_to {
+                let k_out = *out_deg.get(from.as_str()).unwrap_or(&0) as f64;
+                let k_in = *in_deg.get(to.as_str()).unwrap_or(&0) as f64;
+                q += 1.0 - (k_out * k_in / m_f);
+            }
+        }
+    }
+
+    q / m_f
+}
+
+/// Build Circuit structs from detected communities, computing boundary
+/// functions, internal edges, and cohesion for each circuit.
+fn build_circuits(
+    communities: &[Vec<String>],
+    cg: &flow::CallGraph,
+    rev_adj: &HashMap<String, Vec<String>>,
+    partition: &HashMap<String, usize>,
+) -> Vec<Circuit> {
+    let mut circuits: Vec<Circuit> = Vec::new();
+    for (ci, community) in communities.iter().enumerate() {
+        let member_set: HashSet<&str> = community.iter().map(|s| s.as_str()).collect();
+
+        // Boundary functions: called from outside the circuit
+        let mut boundary_fns = Vec::new();
+        for member in community {
+            let is_boundary = rev_adj.get(member.as_str()).map_or(false, |callers| {
+                callers
+                    .iter()
+                    .any(|c| partition.get(c.as_str()).copied().unwrap_or(ci) != ci)
+            });
+            if is_boundary {
+                boundary_fns.push(member.clone());
+            }
+        }
+        boundary_fns.sort();
+
+        // Internal edges: edges where both endpoints are in this circuit
+        let mut internal_edges = 0usize;
+        for member in community {
+            if let Some(callees) = cg.adjacency.get(member.as_str()) {
+                for callee in callees {
+                    if member_set.contains(callee.as_str()) {
+                        internal_edges += 1;
+                    }
+                }
+            }
+        }
+
+        // Cohesion: internal edges / possible internal edges
+        let n = community.len();
+        let possible = if n > 1 { n * (n - 1) } else { 1 };
+        let cohesion = internal_edges as f64 / possible as f64;
+
+        circuits.push(Circuit {
+            members: community.clone(),
+            boundary_fns,
+            internal_edges,
+            cohesion,
+        });
+    }
+    circuits
+}
+
+/// Compute inter-circuit edges: count directed call edges between each
+/// pair of circuits, returned sorted by weight (heaviest first).
+fn compute_inter_circuit_edges(
+    cg: &flow::CallGraph,
+    partition: &HashMap<String, usize>,
+) -> Vec<(usize, usize, usize)> {
+    let mut inter_edges: HashMap<(usize, usize), usize> = HashMap::new();
+    for (caller, callees) in &cg.adjacency {
+        let c_from = match partition.get(caller.as_str()) {
+            Some(&c) => c,
+            None => continue,
+        };
+        for callee in callees {
+            let c_to = match partition.get(callee.as_str()) {
+                Some(&c) => c,
+                None => continue,
+            };
+            if c_from != c_to {
+                *inter_edges.entry((c_from, c_to)).or_insert(0) += 1;
+            }
+        }
+    }
+
+    let mut result: Vec<(usize, usize, usize)> = inter_edges
+        .into_iter()
+        .map(|((a, b), w)| (a, b, w))
+        .collect();
+    result.sort_by(|a, b| b.2.cmp(&a.2));
+    result
+}
+
+/// Run full circuit analysis on the call graph.
+fn analyze_circuits(cg: &flow::CallGraph, min_size: usize) -> CircuitAnalysis {
+    // Build reverse adjacency
+    let mut rev_adj: HashMap<String, Vec<String>> = HashMap::new();
+    for f in &cg.functions {
+        rev_adj.entry(f.clone()).or_default();
+    }
+    for (caller, callees) in &cg.adjacency {
+        for callee in callees {
+            rev_adj
+                .entry(callee.clone())
+                .or_default()
+                .push(caller.clone());
+        }
+    }
+
+    let communities = label_propagation(&cg.functions, &cg.adjacency, &rev_adj);
+
+    // Build partition map: node -> circuit index
+    let mut partition: HashMap<String, usize> = HashMap::new();
+    for (ci, community) in communities.iter().enumerate() {
+        for node in community {
+            partition.insert(node.clone(), ci);
+        }
+    }
+
+    let circuits = build_circuits(&communities, cg, &rev_adj, &partition);
+    let inter_circuit_edges = compute_inter_circuit_edges(cg, &partition);
+    let modularity = compute_modularity(&cg.functions, &cg.adjacency, &partition);
+
+    // Filter by min_size
+    let filtered_circuits: Vec<Circuit> = circuits
+        .into_iter()
+        .filter(|c| c.members.len() >= min_size)
+        .collect();
+
+    CircuitAnalysis {
+        circuits: filtered_circuits,
+        inter_circuit_edges,
+        modularity,
+    }
+}
+
+fn render_overview(analysis: &CircuitAnalysis, total_functions: usize, verbose: bool) {
+    println!(
+        "\n{}",
+        "── Circuit Overview ──────────────────────────────────"
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Community detection via label propagation on the call graph.",
+            "Each node starts with its own label; iteratively adopts the most frequent",
+            "neighbor label until stable. Produces functional clusters (circuits).",
+            "Modularity Q measures partition quality: Q > 0.3 = well-separated modules,",
+            "  Q ≈ 0 = random partition, Q < 0 = worse than random.",
+            "Sparkline shows relative circuit sizes (█ = largest, ▁ = smallest).",
+        ]);
+        render::guide_ref("modularity");
+    }
+
+    let sizes: Vec<usize> = analysis.circuits.iter().map(|c| c.members.len()).collect();
+
+    println!();
+    println!("  ┌──────────────────────────────────────┐");
+    println!(
+        "  │ {:<18} {:>17} │",
+        "Circuits".cyan(),
+        format!("{}", analysis.circuits.len()).bold()
+    );
+    println!(
+        "  │ {:<18} {:>17} │",
+        "Functions covered".cyan(),
+        format!("{}", total_functions).bold()
+    );
+    if !sizes.is_empty() {
+        let max_size = sizes.iter().max().unwrap_or(&0);
+        let min_size = sizes.iter().min().unwrap_or(&0);
+        let avg_size = sizes.iter().sum::<usize>() as f64 / sizes.len() as f64;
+        println!(
+            "  │ {:<18} {:>17} │",
+            "Largest circuit".cyan(),
+            format!("{}", max_size).bold()
+        );
+        println!(
+            "  │ {:<18} {:>17} │",
+            "Smallest circuit".cyan(),
+            format!("{}", min_size).bold()
+        );
+        println!(
+            "  │ {:<18} {:>17} │",
+            "Average size".cyan(),
+            format!("{:.1}", avg_size).bold()
+        );
+    }
+    println!(
+        "  │ {:<18} {:>17} │",
+        "Modularity (Q)".cyan(),
+        if analysis.modularity > 0.0 {
+            format!("{:.4}", analysis.modularity)
+                .green()
+                .bold()
+                .to_string()
+        } else {
+            format!("{:.4}", analysis.modularity)
+                .red()
+                .bold()
+                .to_string()
+        }
+    );
+    println!("  └──────────────────────────────────────┘");
+
+    // Size distribution sparkline
+    if sizes.len() > 1 {
+        let max_s = *sizes.iter().max().unwrap_or(&1) as f64;
+        let blocks = ['▁', '▂', '▃', '▄', '▅', '▆', '▇', '█'];
+        let sparkline: String = sizes
+            .iter()
+            .map(|&s| {
+                let idx = ((s as f64 / max_s) * 7.0).round() as usize;
+                blocks[idx.min(7)]
+            })
+            .collect();
+        println!(
+            "\n  {} {}",
+            "Size distribution:".dimmed(),
+            sparkline.bright_yellow()
+        );
+    }
+}
+
+fn render_circuit_details(analysis: &CircuitAnalysis, verbose: bool) {
+    println!(
+        "\n{}",
+        "── Circuits (by size) ────────────────────────────────"
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Each circuit listed with its members, sorted by size (largest first).",
+            "Cohesion = internal edges / possible internal edges. Higher = tighter cluster.",
+            "  1.0 = every pair of members calls each other; 0.0 = no internal calls.",
+            "◆ (blue) = boundary function: called from outside the circuit = the circuit's",
+            "  API surface. These are the functions other circuits depend on.",
+            "· (dim) = internal function: only called from within the same circuit.",
+            "'Connects to' = other circuits this one exchanges calls with (weight = edge count).",
+        ]);
+    }
+
+    for (i, circuit) in analysis.circuits.iter().enumerate() {
+        println!();
+        let header = format!(
+            "  Circuit #{} — {} function{}",
+            i + 1,
+            circuit.members.len(),
+            if circuit.members.len() == 1 { "" } else { "s" },
+        );
+        println!("{}", header.yellow().bold());
+
+        // Stats line
+        println!(
+            "    Cohesion: {:.2}   Internal edges: {}   Boundary fns: {}",
+            circuit.cohesion,
+            circuit.internal_edges,
+            circuit.boundary_fns.len(),
+        );
+
+        // Members, marking boundary functions
+        let boundary_set: HashSet<&str> = circuit.boundary_fns.iter().map(|s| s.as_str()).collect();
+
+        for member in &circuit.members {
+            if boundary_set.contains(member.as_str()) {
+                println!("    {} {}", "◆".bright_blue(), member.bright_white(),);
+            } else {
+                println!("    {} {}", "·".dimmed(), member.dimmed(),);
+            }
+        }
+
+        // External dependencies for this circuit
+        let circuit_deps: Vec<&(usize, usize, usize)> = analysis
+            .inter_circuit_edges
+            .iter()
+            .filter(|(from, to, _)| *from == i || *to == i)
+            .collect();
+
+        if !circuit_deps.is_empty() {
+            let mut dep_summary: Vec<(usize, usize)> = Vec::new(); // (other_circuit, total_weight)
+            let mut seen: HashSet<usize> = HashSet::new();
+            for &&(from, to, _w) in &circuit_deps {
+                let other = if from == i { to } else { from };
+                if seen.insert(other) {
+                    // Sum both directions
+                    let total: usize = analysis
+                        .inter_circuit_edges
+                        .iter()
+                        .filter(|(a, b, _)| (*a == i && *b == other) || (*a == other && *b == i))
+                        .map(|(_, _, w)| w)
+                        .sum();
+                    dep_summary.push((other, total));
+                }
+            }
+            dep_summary.sort_by(|a, b| b.1.cmp(&a.1));
+
+            print!("    {} ", "Connects to:".dimmed());
+            let dep_strs: Vec<String> = dep_summary
+                .iter()
+                .take(5)
+                .map(|(other, w)| format!("#{} ({})", other + 1, w))
+                .collect();
+            println!("{}", dep_strs.join(", ").dimmed());
+        }
+    }
+}
+
+fn render_inter_circuit_flow(analysis: &CircuitAnalysis, verbose: bool) {
+    println!(
+        "\n{}",
+        "── Inter-Circuit Flow ────────────────────────────────"
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Cross-circuit call volume between each pair of circuits.",
+            "⇄ = bidirectional coupling (calls flow both ways between the two circuits).",
+            "→ / ← = unidirectional flow. Number = total call edges between the pair.",
+            "Bar length proportional to total edge count. Color: red = heaviest coupling,",
+            "  yellow = moderate, green = light.",
+            "High bidirectional coupling between circuits suggests they may belong together",
+            "or need a cleaner interface boundary.",
+        ]);
+    }
+
+    if analysis.inter_circuit_edges.is_empty() {
+        println!("  {}", "No cross-circuit calls detected.".dimmed());
+        return;
+    }
+
+    // Aggregate bidirectional: merge (a→b) and (b→a) into one row
+    let mut pairs: HashMap<(usize, usize), (usize, usize)> = HashMap::new(); // (min, max) -> (fwd, bwd)
+    for &(from, to, w) in &analysis.inter_circuit_edges {
+        let key = if from <= to { (from, to) } else { (to, from) };
+        let entry = pairs.entry(key).or_insert((0, 0));
+        if from <= to {
+            entry.0 += w;
+        } else {
+            entry.1 += w;
+        }
+    }
+
+    let mut pair_list: Vec<((usize, usize), usize, usize)> = pairs
+        .into_iter()
+        .map(|((a, b), (fwd, bwd))| ((a, b), fwd, bwd))
+        .collect();
+    pair_list.sort_by(|a, b| (b.1 + b.2).cmp(&(a.1 + a.2)));
+
+    let term_w = render::terminal_width();
+    let bar_budget = 20.min(term_w.saturating_sub(40));
+    let max_weight = pair_list.iter().map(|(_, f, b)| f + b).max().unwrap_or(1);
+
+    println!();
+    for ((a, b), fwd, bwd) in pair_list.iter().take(15) {
+        let total = fwd + bwd;
+        let bar_len = if max_weight > 0 {
+            (total as f64 / max_weight as f64 * bar_budget as f64).ceil() as usize
+        } else {
+            0
+        }
+        .max(1);
+
+        let bar = "█".repeat(bar_len);
+        let ratio = total as f64 / max_weight as f64;
+        let colored_bar = if ratio > 0.66 {
+            bar.red().bold().to_string()
+        } else if ratio > 0.33 {
+            bar.yellow().to_string()
+        } else {
+            bar.green().to_string()
+        };
+
+        let direction = if *fwd > 0 && *bwd > 0 {
+            format!("#{} ⇄ #{}", a + 1, b + 1)
+        } else if *fwd > 0 {
+            format!("#{} → #{}", a + 1, b + 1)
+        } else {
+            format!("#{} ← #{}", a + 1, b + 1)
+        };
+
+        println!(
+            "    {:<16} {} {}",
+            direction,
+            colored_bar,
+            format!("{} calls", total).dimmed(),
+        );
+    }
+
+    if pair_list.len() > 15 {
+        println!(
+            "    {}",
+            format!("... and {} more connections", pair_list.len() - 15).dimmed()
+        );
+    }
+
+    println!();
+}
+
+/// Compact summary data for embedding in the dashboard.
+pub struct CircuitSummary {
+    /// Number of circuits.
+    pub circuit_count: usize,
+    /// Size of each circuit (largest first).
+    pub sizes: Vec<usize>,
+    /// Modularity score.
+    pub modularity: f64,
+}
+
+/// Compute compact circuit summary for dashboard use.
+pub fn circuit_summary(rs_files: &[PathBuf], project_path: &Path) -> Option<CircuitSummary> {
+    let cg = flow::build_call_graph(rs_files, project_path);
+    if cg.functions.is_empty() {
+        return None;
+    }
+    let analysis = analyze_circuits(&cg, 1);
+    if analysis.circuits.is_empty() {
+        return None;
+    }
+    let sizes: Vec<usize> = analysis.circuits.iter().map(|c| c.members.len()).collect();
+    Some(CircuitSummary {
+        circuit_count: analysis.circuits.len(),
+        sizes,
+        modularity: analysis.modularity,
+    })
+}
+
+// ── Public entry point ───────────────────────────────────────────
+
+pub fn render_circuits(rs_files: &[PathBuf], project_path: &Path, min_size: usize, verbose: bool) {
+    let cg = flow::build_call_graph(rs_files, project_path);
+
+    if cg.functions.is_empty() {
+        println!("{}", "No functions found for circuit analysis.".yellow());
+        return;
+    }
+
+    let total_functions = cg.functions.len();
+    let analysis = analyze_circuits(&cg, min_size);
+
+    if analysis.circuits.is_empty() {
+        println!(
+            "{}",
+            "No circuits found (try lowering --min-size).".yellow()
+        );
+        return;
+    }
+
+    render_overview(&analysis, total_functions, verbose);
+    render_circuit_details(&analysis, verbose);
+    render_inter_circuit_flow(&analysis, verbose);
+}
+
+#[derive(Serialize)]
+struct CircuitJson {
+    members: Vec<String>,
+    boundary_functions: Vec<String>,
+    internal_edges: usize,
+    cohesion: f64,
+}
+
+#[derive(Serialize)]
+struct InterCircuitEdgeJson {
+    from_circuit: usize,
+    to_circuit: usize,
+    weight: usize,
+}
+
+#[derive(Serialize)]
+struct CircuitsOutputJson {
+    cstat_version: String,
+    circuits: Vec<CircuitJson>,
+    inter_circuit_edges: Vec<InterCircuitEdgeJson>,
+    modularity: f64,
+}
+
+/// Render circuits analysis as JSON.
+pub fn render_circuits_json(rs_files: &[PathBuf], project_path: &Path, min_size: usize) {
+    let cg = flow::build_call_graph(rs_files, project_path);
+    let analysis = analyze_circuits(&cg, min_size);
+
+    let circuits: Vec<CircuitJson> = analysis
+        .circuits
+        .iter()
+        .map(|c| CircuitJson {
+            members: c.members.clone(),
+            boundary_functions: c.boundary_fns.clone(),
+            internal_edges: c.internal_edges,
+            cohesion: c.cohesion,
+        })
+        .collect();
+
+    let inter_circuit_edges: Vec<InterCircuitEdgeJson> = analysis
+        .inter_circuit_edges
+        .iter()
+        .map(|(from, to, w)| InterCircuitEdgeJson {
+            from_circuit: *from,
+            to_circuit: *to,
+            weight: *w,
+        })
+        .collect();
+
+    let output = CircuitsOutputJson {
+        cstat_version: env!("CARGO_PKG_VERSION").to_string(),
+        circuits,
+        inter_circuit_edges,
+        modularity: analysis.modularity,
+    };
+
+    println!("{}", serde_json::to_string(&output).unwrap());
+}

src/commands.rs

@@ -0,0 +1,108 @@
+use std::path::{Path, PathBuf};
+
+#[path = "dist.rs"]
+pub(crate) mod dist;
+#[path = "dump.rs"]
+pub(crate) mod dump;
+#[path = "guide.rs"]
+pub(crate) mod guide;
+#[path = "map.rs"]
+pub(crate) mod map;
+#[path = "summary/mod.rs"]
+pub(crate) mod summary;
+
+use crate::{circuits, complexity, datapaths, deps, flow, graph, loc, redundancy};
+
+pub enum Command {
+    Summary,
+    Loc { top: Option<usize> },
+    Branching,
+    Signature,
+    Span,
+    Deps { top: Option<usize> },
+    Map,
+    Flow,
+    Graph { call_only: bool, dep_only: bool, top: usize },
+    Datapaths { walks: usize, from: Option<String> },
+    Dist { metric: Option<String>, bins: usize },
+    Circuits { min_size: usize },
+    Redundancy,
+    Dump,
+    Guide { topic: Option<String> },
+}
+
+fn canon(project_path: &Path) -> PathBuf {
+    project_path
+        .canonicalize()
+        .unwrap_or_else(|_| project_path.to_path_buf())
+}
+
+/// Run one of two closures depending on the `json` flag.
+fn run_json_or_human<F1, F2>(json: bool, json_fn: F1, human_fn: F2)
+where
+    F1: FnOnce(),
+    F2: FnOnce(),
+{
+    if json {
+        json_fn();
+    } else {
+        human_fn();
+    }
+}
+
+pub fn dispatch(command: Command, rs_files: &[PathBuf], project_path: &Path, json: bool, verbose: bool) {
+    let p = canon(project_path);
+    match command {
+        Command::Summary => run_json_or_human(json,
+            || summary::render_summary_json(rs_files, &p),
+            || summary::render_summary(rs_files, &p, verbose),
+        ),
+        Command::Loc { top } => run_json_or_human(json,
+            || loc::render_loc_json(rs_files, &p),
+            || loc::render_loc(rs_files, &p, top, verbose),
+        ),
+        Command::Branching => complexity::run_branching(rs_files, &p, json, verbose),
+        Command::Signature => complexity::run_signature(rs_files, &p, json, verbose),
+        Command::Span => complexity::run_span(rs_files, &p, json, verbose),
+        Command::Deps { top } => run_json_or_human(json,
+            || deps::render_deps_json(rs_files, &p),
+            || deps::render_deps(rs_files, &p, top, verbose),
+        ),
+        Command::Map => run_json_or_human(json,
+            || map::render_map_json(rs_files, &p),
+            || map::render_map(rs_files, &p, verbose),
+        ),
+        Command::Flow => run_json_or_human(json,
+            || flow::render_flow_json(rs_files, &p),
+            || flow::render_flow(rs_files, &p, verbose),
+        ),
+        Command::Graph { call_only, dep_only, top } => run_json_or_human(json,
+            || graph::render_graph_json(rs_files, &p, call_only, dep_only),
+            || graph::render_graph(rs_files, &p, call_only, dep_only, top, verbose),
+        ),
+        Command::Datapaths { walks, from } => run_json_or_human(json,
+            || datapaths::render_datapaths_json(rs_files, &p, walks, from.as_deref()),
+            || datapaths::render_datapaths(rs_files, &p, walks, from.as_deref(), verbose),
+        ),
+        Command::Dist { metric, bins } => run_json_or_human(json,
+            || dist::render_dist_json(rs_files, &p, metric.as_deref(), bins),
+            || dist::render_dist(rs_files, &p, metric.as_deref(), bins, verbose),
+        ),
+        Command::Circuits { min_size } => run_json_or_human(json,
+            || circuits::render_circuits_json(rs_files, &p, min_size),
+            || circuits::render_circuits(rs_files, &p, min_size, verbose),
+        ),
+        Command::Redundancy => run_json_or_human(json,
+            || redundancy::render_redundancy_json(rs_files, &p),
+            || redundancy::render_redundancy(rs_files, &p, verbose),
+        ),
+        Command::Dump => {
+            colored::control::set_override(false);
+            dump::render_dump(rs_files, &p);
+        }
+        Command::Guide { topic } => match topic {
+            Some(t) => guide::render_guide_topic(&t, json),
+            None => guide::render_guide_toc(json),
+        },
+    }
+}

src/complexity.rs

@@ -1,10 +1,34 @@
 use colored::Colorize;
 use serde::Serialize;
 use std::path::{Path, PathBuf};
+use syn::visit::Visit;
+use syn::Expr;
 
 use crate::ast_parser::{FunctionInfo, ProjectSymbols};
 use crate::render;
 
+/// Complexity metrics for a single function.
+#[derive(Debug, Clone)]
+pub struct FunctionComplexity {
+    pub name: String,
+    pub file: String,
+    pub cyclomatic: usize,
+    pub cognitive: usize,
+    pub nesting_depth: usize,
+    pub composite_score: f64,
+    pub line_count: usize,
+    pub param_count: usize,
+}
+
+/// Aggregate stats across all functions.
+pub struct ComplexityStats {
+    pub total_functions: usize,
+    pub mean: f64,
+    pub std_dev: f64,
+    pub median: f64,
+    pub max: f64,
+}
+
 #[derive(Debug, Clone, Serialize)]
 pub struct BranchingRow {
     pub function: String,
@@ -61,6 +85,320 @@ struct SpanJson {
     functions: Vec<SpanRow>,
 }
 
+/// Compute complexity metrics for a single function.
+fn compute_function_complexity(func: &FunctionInfo, source: &str) -> FunctionComplexity {
+    // Cyclomatic = branch_points + 1
+    let cyclomatic = func.branch_points + 1;
+
+    // Cognitive complexity: re-parse the function body for weighted nesting penalties
+    let cognitive = compute_cognitive_complexity(func, source);
+
+    // Generic complexity: type params + trait bounds + where predicates
+    let generic_complexity =
+        func.generic_param_count + func.trait_bound_count + func.where_predicate_count;
+
+    // Parameter complexity: params weighted by return type complexity
+    let param_complexity = func.param_count + func.return_type_complexity;
+
+    // Composite score: weighted combination
+    let composite_score = cyclomatic as f64 * 1.0
+        + cognitive as f64 * 0.5
+        + func.nesting_depth as f64 * 0.3
+        + generic_complexity as f64 * 0.2
+        + param_complexity as f64 * 0.1;
+
+    let line_count = function_line_count(func);
+
+    FunctionComplexity {
+        name: func.name.clone(),
+        file: func.file.display().to_string(),
+        cyclomatic,
+        cognitive,
+        nesting_depth: func.nesting_depth,
+        composite_score,
+        line_count,
+        param_count: func.param_count,
+    }
+}
+
+/// Compute cognitive complexity for a function.
+/// Increments for each control flow break, with extra penalties for nesting.
+/// Based on SonarSource's cognitive complexity model.
+fn compute_cognitive_complexity(func: &FunctionInfo, source: &str) -> usize {
+    // Try to find and re-parse the function to walk its body with cognitive scoring
+    // We use the already-extracted data as a fallback
+    if let Some(cog) = try_cognitive_from_source(func, source) {
+        return cog;
+    }
+    // Fallback: estimate from extracted data
+    // branch_points + nesting_depth penalty
+    func.branch_points + func.nesting_depth
+}
+
+/// Try to compute cognitive complexity by re-parsing the source file and finding the function.
+fn try_cognitive_from_source(func: &FunctionInfo, source: &str) -> Option<usize> {
+    let ast = syn::parse_file(source).ok()?;
+    let mut finder = CognitiveFinder {
+        target_name: func.name.clone(),
+        result: None,
+    };
+    finder.walk_items(&ast.items);
+    finder.result
+}
+
+struct CognitiveFinder {
+    target_name: String,
+    result: Option<usize>,
+}
+
+impl CognitiveFinder {
+    fn walk_items(&mut self, items: &[syn::Item]) {
+        for item in items {
+            match item {
+                syn::Item::Fn(f) => {
+                    if f.sig.ident == self.target_name {
+                        let mut visitor = CognitiveVisitor::new();
+                        visitor.visit_block(&f.block);
+                        self.result = Some(visitor.complexity);
+                    }
+                }
+                syn::Item::Impl(imp) => {
+                    for impl_item in &imp.items {
+                        if let syn::ImplItem::Fn(method) = impl_item {
+                            let target_type = crate::ast_parser::type_to_string_pub(&imp.self_ty);
+                            let qualified = format!("{}::{}", target_type, method.sig.ident);
+                            if qualified == self.target_name {
+                                let mut visitor = CognitiveVisitor::new();
+                                visitor.visit_block(&method.block);
+                                self.result = Some(visitor.complexity);
+                            }
+                        }
+                    }
+                }
+                _ => {}
+            }
+        }
+    }
+}
+
+/// Visitor that computes cognitive complexity using SonarSource-style rules:
+/// - +1 for each control flow break (if, else if, else, match, for, while, loop, break, continue, &&, ||)
+/// - +1 nesting increment for each level of nesting when encountering a break
+struct CognitiveVisitor {
+    nesting: usize,
+    complexity: usize,
+}
+
+impl CognitiveVisitor {
+    fn new() -> Self {
+        Self {
+            nesting: 0,
+            complexity: 0,
+        }
+    }
+
+    fn increment(&mut self) {
+        // +1 for the construct, +nesting for nesting penalty
+        self.complexity += 1 + self.nesting;
+    }
+
+    fn increment_no_nesting(&mut self) {
+        self.complexity += 1;
+    }
+
+    fn count_boolean_chains(expr: &Expr) -> usize {
+        match expr {
+            Expr::Binary(bin) => {
+                use syn::BinOp;
+                let is_logical = matches!(bin.op, BinOp::And(_) | BinOp::Or(_));
+                let left = Self::count_boolean_chains(&bin.left);
+                let right = Self::count_boolean_chains(&bin.right);
+                left + right + if is_logical { 1 } else { 0 }
+            }
+            _ => 0,
+        }
+    }
+
+    /// Handle `if / else if / else` expressions for cognitive complexity.
+    fn handle_if_expr(&mut self, expr_if: &syn::ExprIf) {
+        self.increment();
+        // Count boolean operators in condition
+        self.complexity += Self::count_boolean_chains(&expr_if.cond);
+        self.nesting += 1;
+        // Visit then branch
+        for stmt in &expr_if.then_branch.stmts {
+            syn::visit::visit_stmt(self, stmt);
+        }
+        self.nesting -= 1;
+        // Visit else branch
+        if let Some((_, else_expr)) = &expr_if.else_branch {
+            self.handle_else_branch(else_expr);
+        }
+    }
+
+    /// Handle the else branch of an if expression.
+    /// Matches original behavior: first else-if is handled inline with no nesting
+    /// penalty, and deeper else branches delegate back to visit_expr.
+    fn handle_else_branch(&mut self, else_expr: &Expr) {
+        match else_expr {
+            Expr::If(inner_if) => {
+                // else if: +1 no nesting penalty (it's a continuation)
+                self.increment_no_nesting();
+                // But the inner if body still gets nesting
+                self.complexity += Self::count_boolean_chains(&inner_if.cond);
+                self.nesting += 1;
+                for stmt in &inner_if.then_branch.stmts {
+                    syn::visit::visit_stmt(self, stmt);
+                }
+                self.nesting -= 1;
+                if let Some((_, inner_else)) = &inner_if.else_branch {
+                    self.handle_inner_else(inner_else);
+                }
+            }
+            Expr::Block(block) => {
+                self.increment_no_nesting();
+                self.nesting += 1;
+                for stmt in &block.block.stmts {
+                    syn::visit::visit_stmt(self, stmt);
+                }
+                self.nesting -= 1;
+            }
+            _ => {
+                syn::visit::visit_expr(self, else_expr);
+            }
+        }
+    }
+
+    /// Handle deeper else branches (third level and beyond).
+    /// Delegates Expr::If back to visit_expr for standard increment-with-nesting,
+    /// matching the original behavior.
+    fn handle_inner_else(&mut self, else_expr: &Expr) {
+        match else_expr {
+            Expr::If(_) => {
+                self.visit_expr(else_expr);
+            }
+            Expr::Block(block) => {
+                self.increment_no_nesting();
+                self.nesting += 1;
+                for stmt in &block.block.stmts {
+                    syn::visit::visit_stmt(self, stmt);
+                }
+                self.nesting -= 1;
+            }
+            _ => {}
+        }
+    }
+
+    /// Handle `match` expressions for cognitive complexity.
+    fn handle_match_expr(&mut self, m: &syn::ExprMatch) {
+        self.increment();
+        self.nesting += 1;
+        for arm in &m.arms {
+            if arm.guard.is_some() {
+                self.increment_no_nesting();
+            }
+            syn::visit::visit_expr(self, &arm.body);
+        }
+        self.nesting -= 1;
+    }
+
+    /// Handle `for`, `while`, and `loop` expressions for cognitive complexity.
+    fn handle_loop_expr(&mut self, expr: &Expr) {
+        self.increment();
+        self.nesting += 1;
+        syn::visit::visit_expr(self, expr);
+        self.nesting -= 1;
+    }
+}
+
+impl<'ast> Visit<'ast> for CognitiveVisitor {
+    fn visit_expr(&mut self, expr: &'ast Expr) {
+        match expr {
+            Expr::If(expr_if) => {
+                self.handle_if_expr(expr_if);
+                return;
+            }
+            Expr::Match(m) => {
+                self.handle_match_expr(m);
+                return;
+            }
+            Expr::ForLoop(_) | Expr::While(_) | Expr::Loop(_) => {
+                self.handle_loop_expr(expr);
+                return;
+            }
+            Expr::Break(_) | Expr::Continue(_) => {
+                self.increment_no_nesting();
+            }
+            Expr::Closure(_) => {
+                self.nesting += 1;
+                syn::visit::visit_expr(self, expr);
+                self.nesting -= 1;
+                return;
+            }
+            _ => {}
+        }
+        syn::visit::visit_expr(self, expr);
+    }
+}
+
+/// Compute complexity for all functions in the project.
+pub fn compute_all(symbols: &ProjectSymbols, project_path: &Path) -> Vec<FunctionComplexity> {
+    let mut results = Vec::new();
+
+    for file_syms in &symbols.files {
+        let source = std::fs::read_to_string(&file_syms.path).unwrap_or_default();
+
+        for func in &file_syms.functions {
+            let fc = compute_function_complexity(func, &source);
+            results.push(FunctionComplexity {
+                file: strip_project_path(&fc.file, project_path),
+                ..fc
+            });
+        }
+    }
+
+    // Sort by composite score descending
+    results.sort_by(|a, b| {
+        b.composite_score
+            .partial_cmp(&a.composite_score)
+            .unwrap_or(std::cmp::Ordering::Equal)
+    });
+    results
+}
+
+/// Compute per-file complexity aggregation.
+
+/// Compute aggregate stats across all function complexities.
+pub fn compute_stats(complexities: &[FunctionComplexity]) -> Option<ComplexityStats> {
+    if complexities.is_empty() {
+        return None;
+    }
+
+    let total = complexities.len();
+    let scores: Vec<f64> = complexities.iter().map(|c| c.composite_score).collect();
+    let sum: f64 = scores.iter().sum();
+    let mean = sum / total as f64;
+    let variance = scores.iter().map(|s| (s - mean) * (s - mean)).sum::<f64>() / total as f64;
+    let std_dev = variance.sqrt();
+
+    let mut sorted = scores.clone();
+    sorted.sort_by(|a, b| a.partial_cmp(b).unwrap_or(std::cmp::Ordering::Equal));
+    let median = if total % 2 == 0 {
+        (sorted[total / 2 - 1] + sorted[total / 2]) / 2.0
+    } else {
+        sorted[total / 2]
+    };
+    let max = sorted.last().copied().unwrap_or(0.0);
+
+    Some(ComplexityStats {
+        total_functions: total,
+        mean,
+        std_dev,
+        median,
+        max,
+    })
+}
+
 fn strip_project_path(path: &str, project_path: &Path) -> String {
     let prefix = project_path.display().to_string();
     let stripped = path.strip_prefix(&prefix).unwrap_or(path);

src/coverage.rs

@@ -58,24 +58,14 @@ pub struct ToolStatus {
     pub llvm_profdata: Option<String>,
     pub profile_dir: Option<String>,
     pub export_source: String,
-    pub branch_instrumentation_enabled: Option<bool>,
 }
 
-const COVERAGE_VERBOSE_INTRO: &[&str] = &[
-    "Normal mode runs cargo test with Rust source-based coverage flags before reading llvm-cov export data.",
-    "Use coverage --no-run with CSTAT_LLVM_COV_EXPORT_JSON to analyze an existing llvm-cov export.",
-    "Line coverage is dynamic llvm-cov segment data; branch coverage uses branch records when the Rust/LLVM toolchain emits them.",
-    "Production spans exclude tests, benches, test-support helpers, and selected src/bin wrapper main().",
-    "Selected-file static/projected sections are static reachability context, not runtime coverage.",
-];
-
 pub fn render_coverage(
     rs_files: &[PathBuf],
     project_path: &Path,
     selected_file: Option<&Path>,
     no_run: bool,
     json: bool,
-    verbose: bool,
 ) -> Result<(), String> {
     let symbols = ast_parser::parse_project(rs_files);
     let graph = flow::build_call_graph(rs_files, project_path);
@@ -87,37 +77,24 @@ pub fn render_coverage(
         selected_file,
     );
 
-    let export_result = if no_run {
+    let (export_json, mut status) = if no_run {
         let export_path = std::env::var("CSTAT_LLVM_COV_EXPORT_JSON").map_err(|_| {
             "CSTAT_LLVM_COV_EXPORT_JSON is required when coverage --no-run is used".to_string()
-        });
-        export_path.and_then(|export_path| {
-            let content = std::fs::read_to_string(&export_path).map_err(|e| {
-                format!("failed to read CSTAT_LLVM_COV_EXPORT_JSON={export_path}: {e}")
-            })?;
-            Ok((
-                content,
-                ToolStatus {
-                    ran_tests: false,
-                    llvm_cov: None,
-                    llvm_profdata: None,
-                    profile_dir: None,
-                    branch_instrumentation_enabled: None,
-                    export_source: export_path,
-                },
-            ))
-        })
+        })?;
+        let content = std::fs::read_to_string(&export_path)
+            .map_err(|e| format!("failed to read CSTAT_LLVM_COV_EXPORT_JSON={export_path}: {e}"))?;
+        (
+            content,
+            ToolStatus {
+                ran_tests: false,
+                llvm_cov: None,
+                llvm_profdata: None,
+                profile_dir: None,
+                export_source: export_path,
+            },
+        )
     } else {
-        collect_coverage_export(project_path, selected_file)
-    };
-    let (export_json, mut status) = match export_result {
-        Ok(result) => result,
-        Err(message) => {
-            if verbose && !json {
-                render_coverage_verbose_intro();
-            }
-            return Err(message);
-        }
+        collect_coverage_export(project_path, selected_file)?
     };
 
     let mut report = analyze_export_json(&export_json, project_path, selected_file, &filter)?;
@@ -154,7 +131,7 @@ pub fn render_coverage(
             serde_json::to_string(&report).map_err(|e| e.to_string())?
         );
     } else {
-        render_coverage_report(&report, selected_file.is_some(), &status, verbose);
+        render_coverage_report(&report, selected_file.is_some(), &status);
     }
     Ok(())
 }
@@ -322,21 +299,11 @@ pub fn analyze_export_json(
             llvm_profdata: None,
             profile_dir: None,
             export_source: "provided_json".to_string(),
-            branch_instrumentation_enabled: None,
         },
     })
 }
 
-fn render_coverage_verbose_intro() {
-    render::verbose_block(COVERAGE_VERBOSE_INTRO);
-}
-
-fn render_coverage_report(
-    report: &CoverageReport,
-    selected_file: bool,
-    status: &ToolStatus,
-    verbose: bool,
-) {
+fn render_coverage_report(report: &CoverageReport, selected_file: bool, status: &ToolStatus) {
     println!(
         "\n{} {}",
         "cstat coverage".bright_cyan().bold(),
@@ -344,27 +311,19 @@ fn render_coverage_report(
     );
     println!("  {} {}", "source".cyan(), status.export_source);
 
-    if verbose {
-        render_coverage_verbose_intro();
-    }
-
     if selected_file {
+        render::section_header("Static test/benchmark reachability");
         if let Some(static_reachability) = &report.static_reachability {
-            datapaths::render_file_static_reachability_report(static_reachability, verbose);
+            datapaths::render_file_static_reachability_report(static_reachability, false);
         }
+        render::section_header("Projected line reachability");
         loc::render_file_projected_line_reachability_report(
             &report.projected_line_reachability,
-            verbose,
+            false,
         );
     }
 
     render::section_header("Dynamic line coverage");
-    if verbose {
-        render::verbose_block(&[
-            "Coverable/executed lines come from llvm-cov segment counts after cstat's production-span filter.",
-            "Missing lines are coverable production lines whose execution count was zero in the export.",
-        ]);
-    }
     println!(
         "  executed lines {} / {} ({:.1}%)  missing {}",
         report
@@ -393,20 +352,11 @@ fn render_coverage_report(
     }
 
     render::section_header("Branch coverage");
-    if verbose {
-        render::verbose_block(&[
-            "Branch coverage counts true/false outcomes from llvm-cov branch records.",
-            "When cstat runs coverage itself, Rust branch records require nightly -Z coverage-options=branch.",
-            "When branch data is absent, cstat reports the section as unavailable instead of inventing branch counts.",
-        ]);
-    }
     if report.branch_coverage.total_branch_outcomes == 0 {
-        let message = match status.branch_instrumentation_enabled {
-            Some(false) => "branch data unavailable: this rustc does not expose nightly -Z coverage-options=branch, so cstat collected line/region coverage only",
-            Some(true) => "branch data unavailable: llvm-cov export contained no branch records for included production files",
-            None => "branch data unavailable: llvm-cov export contained no branch records for included production files",
-        };
-        println!("  {}", message.yellow());
+        println!(
+            "  {}",
+            "branch data unavailable in llvm-cov export".yellow()
+        );
         return;
     }
     println!(
@@ -505,23 +455,6 @@ fn coverage_profile_dir(target_dir: &Path) -> PathBuf {
     target_dir.join("cstat-coverage")
 }
 
-fn captured_command_output(stdout: &[u8], stderr: &[u8]) -> String {
-    let stdout = String::from_utf8_lossy(stdout);
-    let stderr = String::from_utf8_lossy(stderr);
-    let mut details = String::new();
-
-    if !stdout.trim().is_empty() {
-        details.push_str("\n\ncargo test stdout:\n");
-        details.push_str(stdout.trim_end());
-    }
-    if !stderr.trim().is_empty() {
-        details.push_str("\n\ncargo test stderr:\n");
-        details.push_str(stderr.trim_end());
-    }
-
-    details
-}
-
 fn collect_coverage_export(
     project_path: &Path,
     selected_file: Option<&Path>,
@@ -543,16 +476,10 @@ fn collect_coverage_export(
     }
 
     let cargo_args = cargo_test_args(project_path, selected_file);
-    let branch_instrumentation_enabled = rustc_supports_branch_coverage();
-    let existing_rustflags = std::env::var("RUSTFLAGS").ok();
-    let rustflags = coverage_rustflags(
-        existing_rustflags.as_deref(),
-        branch_instrumentation_enabled,
-    );
     let mut cargo = Command::new("cargo");
     cargo.args(&cargo_args);
-    let output = cargo
-        .env("RUSTFLAGS", rustflags)
+    let status = cargo
+        .env("RUSTFLAGS", "-C instrument-coverage -C link-dead-code")
         .env(
             "LLVM_PROFILE_FILE",
             profile_dir
@@ -560,13 +487,11 @@ fn collect_coverage_export(
                 .to_string_lossy()
                 .to_string(),
         )
-        .output()
+        .status()
         .map_err(|e| format!("failed to run cargo test for coverage: {e}"))?;
-    if !output.status.success() {
+    if !status.success() {
         return Err(format!(
-            "cargo test for coverage failed with status {}{}",
-            output.status,
-            captured_command_output(&output.stdout, &output.stderr),
+            "cargo test for coverage failed with status {status}"
         ));
     }
 
@@ -628,7 +553,6 @@ fn collect_coverage_export(
             llvm_profdata: Some(llvm_profdata.to_string_lossy().to_string()),
             profile_dir: Some(profile_dir.to_string_lossy().to_string()),
             export_source: format_command("cargo", &cargo_args),
-            branch_instrumentation_enabled: Some(branch_instrumentation_enabled),
         },
     ))
 }
@@ -771,30 +695,6 @@ fn format_command(program: &str, args: &[String]) -> String {
         .join(" ")
 }
 
-fn coverage_rustflags(existing_rustflags: Option<&str>, enable_branch_coverage: bool) -> String {
-    let mut flags = existing_rustflags
-        .map(str::trim)
-        .filter(|flags| !flags.is_empty())
-        .map(ToString::to_string)
-        .unwrap_or_default();
-    if !flags.is_empty() {
-        flags.push(' ');
-    }
-    flags.push_str("-C instrument-coverage -C link-dead-code");
-    if enable_branch_coverage {
-        flags.push_str(" -Z coverage-options=branch");
-    }
-    flags
-}
-
-fn rustc_supports_branch_coverage() -> bool {
-    let rustc = std::env::var_os("RUSTC").unwrap_or_else(|| std::ffi::OsString::from("rustc"));
-    let Ok(output) = Command::new(rustc).arg("-Z").arg("help").output() else {
-        return false;
-    };
-    output.status.success() && String::from_utf8_lossy(&output.stdout).contains("coverage-options")
-}
-
 fn find_tool(env_key: &str, binary: &str) -> Result<PathBuf, String> {
     if let Some(value) = std::env::var_os(env_key) {
         let path = PathBuf::from(value);
@@ -820,7 +720,7 @@ fn find_tool(env_key: &str, binary: &str) -> Result<PathBuf, String> {
             return Ok(candidate);
         }
     }
-    Err("LLVM coverage tools unavailable; install rustup component llvm-tools-preview or set LLVM_COV and LLVM_PROFDATA, or use coverage --no-run with CSTAT_LLVM_COV_EXPORT_JSON".to_string())
+    Err("LLVM coverage tools unavailable; install rustup component llvm-tools-preview or set LLVM_COV and LLVM_PROFDATA".to_string())
 }
 
 fn rustc_sysroot() -> Result<String, String> {
@@ -1324,22 +1224,6 @@ path = "src/bin/mvp_chat.rs"
         fs::remove_dir_all(root).unwrap();
     }
 
-    #[test]
-    fn coverage_rustflags_preserve_existing_flags_and_enable_branch_option() {
-        assert_eq!(
-            coverage_rustflags(None, false),
-            "-C instrument-coverage -C link-dead-code"
-        );
-        assert_eq!(
-            coverage_rustflags(Some("-C debuginfo=2"), false),
-            "-C debuginfo=2 -C instrument-coverage -C link-dead-code"
-        );
-        assert_eq!(
-            coverage_rustflags(Some("-C debuginfo=2"), true),
-            "-C debuginfo=2 -C instrument-coverage -C link-dead-code -Z coverage-options=branch"
-        );
-    }
-
     #[test]
     fn parses_llvm_export_line_and_branch_sites() {
         let root = temp_project("parser");

src/datapaths.rs

@@ -598,6 +598,589 @@ fn truncate(value: &str, max: usize) -> String {
     }
 }
 
+/// Run many random walks through the call graph and accumulate visit counts.
+fn simulate_walks(
+    graph: &CallGraph,
+    entry_points: &[String],
+    num_walks: usize,
+) -> HashMap<String, usize> {
+    let mut visit_counts: HashMap<String, usize> = HashMap::new();
+    let mut rng_state: u64 = 0xdeadbeef_u64;
+
+    for (ep_idx, entry) in entry_points.iter().enumerate() {
+        let walks_per_entry = num_walks / entry_points.len().max(1);
+        for walk_i in 0..walks_per_entry {
+            rng_state = rng_state.wrapping_mul(6364136223846793005).wrapping_add(
+                (ep_idx as u64)
+                    .wrapping_mul(1442695040888963407)
+                    .wrapping_add(walk_i as u64),
+            );
+            let mut current = entry.clone();
+            let mut steps = 0;
+            let max_steps = 200;
+
+            loop {
+                *visit_counts.entry(current.clone()).or_insert(0) += 1;
+                steps += 1;
+                if steps >= max_steps {
+                    break;
+                }
+
+                let callees = match graph.adjacency.get(&current) {
+                    Some(c) if !c.is_empty() => c,
+                    _ => break,
+                };
+
+                // Simple LCG random choice
+                rng_state = rng_state
+                    .wrapping_mul(6364136223846793005)
+                    .wrapping_add(1442695040888963407);
+                let idx = (rng_state >> 33) as usize % callees.len();
+                current = callees[idx].clone();
+            }
+        }
+    }
+
+    visit_counts
+}
+
+/// Run walks from a single entry point.
+fn simulate_walks_from(graph: &CallGraph, entry: &str, num_walks: usize) -> HashMap<String, usize> {
+    let mut visit_counts: HashMap<String, usize> = HashMap::new();
+    let mut rng_state: u64 = 0xcafebabe_u64;
+
+    for walk_i in 0..num_walks {
+        rng_state = rng_state
+            .wrapping_mul(6364136223846793005)
+            .wrapping_add(walk_i as u64);
+        let mut current = entry.to_string();
+        let mut steps = 0;
+        let max_steps = 200;
+
+        loop {
+            *visit_counts.entry(current.clone()).or_insert(0) += 1;
+            steps += 1;
+            if steps >= max_steps {
+                break;
+            }
+
+            let callees = match graph.adjacency.get(&current) {
+                Some(c) if !c.is_empty() => c,
+                _ => break,
+            };
+
+            rng_state = rng_state
+                .wrapping_mul(6364136223846793005)
+                .wrapping_add(1442695040888963407);
+            let idx = (rng_state >> 33) as usize % callees.len();
+            current = callees[idx].clone();
+        }
+    }
+
+    visit_counts
+}
+
+/// Find the hot path: greedily follow highest-visit-count callees from entry.
+fn find_hot_path(
+    graph: &CallGraph,
+    entry: &str,
+    visit_counts: &HashMap<String, usize>,
+) -> Vec<String> {
+    let mut path = vec![entry.to_string()];
+    let mut visited = HashSet::new();
+    visited.insert(entry.to_string());
+    let mut current = entry.to_string();
+
+    loop {
+        let callees = match graph.adjacency.get(&current) {
+            Some(c) if !c.is_empty() => c,
+            _ => break,
+        };
+
+        // Pick callee with highest visit count
+        let best = callees
+            .iter()
+            .filter(|c| !visited.contains(*c))
+            .max_by_key(|c| visit_counts.get(*c).copied().unwrap_or(0));
+
+        match best {
+            Some(next) => {
+                visited.insert(next.clone());
+                path.push(next.clone());
+                current = next.clone();
+            }
+            None => break,
+        }
+    }
+
+    path
+}
+
+/// Find all functions reachable from any entry point via BFS.
+fn reachable_from_entries(graph: &CallGraph) -> HashSet<String> {
+    let mut reachable = HashSet::new();
+    let mut queue: Vec<String> = graph.entry_points.clone();
+
+    while let Some(node) = queue.pop() {
+        if !reachable.insert(node.clone()) {
+            continue;
+        }
+        if let Some(callees) = graph.adjacency.get(&node) {
+            for callee in callees {
+                if !reachable.contains(callee) {
+                    queue.push(callee.clone());
+                }
+            }
+        }
+    }
+
+    reachable
+}
+
+/// Render the heatmap ranked list.
+fn render_heatmap(visit_counts: &HashMap<String, usize>, total_functions: usize, verbose: bool) {
+    let tw = render::terminal_width();
+    println!(
+        "\n{}",
+        "── Activation Heatmap ────────────────────────────────"
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Random walk activation heatmap: N random walks (default 10,000) start from",
+            "entry points and follow random callees at each step.",
+            "Visit count ≈ runtime activation likelihood — how often each function would",
+            "be hit if entry points were called uniformly at random.",
+            "Color: red/bold = hot (>70% of max), yellow = warm (>40%), blue = cool (>15%),",
+            "  dim = cold (<15%). Percentage = share of all visits across all walks.",
+            "Coverage = fraction of total functions reached by at least one walk.",
+        ]);
+        render::guide_ref("flow");
+    }
+
+    let total_visits: usize = visit_counts.values().sum();
+    if total_visits == 0 {
+        println!("  {}", "No visits recorded.".dimmed());
+        return;
+    }
+
+    let mut ranked: Vec<(&String, &usize)> = visit_counts.iter().collect();
+    ranked.sort_by(|a, b| b.1.cmp(a.1));
+
+    let max_count = *ranked[0].1;
+    let name_width = 40.min(tw.saturating_sub(30));
+    let bar_max = 20.min(tw.saturating_sub(name_width + 20));
+
+    println!();
+    for (name, count) in ranked.iter().take(30) {
+        let pct = **count as f64 / total_visits as f64 * 100.0;
+        let bar_len = (**count as f64 / max_count as f64 * bar_max as f64) as usize;
+
+        let heat = **count as f64 / max_count as f64;
+        let bar = "█".repeat(bar_len);
+        let colored_bar = if heat > 0.7 {
+            bar.red().bold().to_string()
+        } else if heat > 0.4 {
+            bar.yellow().to_string()
+        } else if heat > 0.15 {
+            bar.bright_blue().to_string()
+        } else {
+            bar.dimmed().to_string()
+        };
+
+        let display_name = if name.len() > name_width {
+            format!("…{}", &name[name.len() - name_width + 1..])
+        } else {
+            format!("{:<width$}", name, width = name_width)
+        };
+
+        println!(
+            "  {} {} {:>5.1}%  {}",
+            display_name.dimmed(),
+            colored_bar,
+            pct,
+            format!("({})", count).dimmed(),
+        );
+    }
+
+    if ranked.len() > 30 {
+        println!(
+            "  {} more functions with lower activation.",
+            format!("… +{}", ranked.len() - 30).dimmed()
+        );
+    }
+
+    println!(
+        "\n  {} {} visits across {} functions",
+        "Total:".bold(),
+        total_visits,
+        visit_counts.len(),
+    );
+    println!(
+        "  {} {:.1}%",
+        "Coverage:".bold(),
+        visit_counts.len() as f64 / total_functions.max(1) as f64 * 100.0,
+    );
+}
+
+/// Render per-entry-point breakdown.
+fn render_per_entry(graph: &CallGraph, num_walks: usize, verbose: bool) {
+    if graph.entry_points.is_empty() {
+        return;
+    }
+
+    println!(
+        "\n{}",
+        "── Per-Entry-Point Breakdown ─────────────────────────"
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Same random walks as above, but partitioned by starting entry point.",
+            "Shows how many unique functions each entry point can reach and their",
+            "top-5 most visited callees. Useful for understanding which entry point",
+            "exercises which parts of the codebase.",
+        ]);
+    }
+
+    for entry in &graph.entry_points {
+        let counts = simulate_walks_from(graph, entry, num_walks / graph.entry_points.len().max(1));
+        let total: usize = counts.values().sum();
+        let mut ranked: Vec<(&String, &usize)> = counts.iter().collect();
+        ranked.sort_by(|a, b| b.1.cmp(a.1));
+
+        println!(
+            "\n  {} (reached {} functions, {} total visits)",
+            entry.bold().bright_white(),
+            counts.len(),
+            total,
+        );
+
+        let top5: Vec<_> = ranked.iter().take(5).collect();
+        for (name, count) in &top5 {
+            let pct = **count as f64 / total.max(1) as f64 * 100.0;
+            println!("    {:<40} {:>5.1}%", name.dimmed(), pct);
+        }
+        if ranked.len() > 5 {
+            println!("    {}", format!("… +{} more", ranked.len() - 5).dimmed());
+        }
+    }
+}
+
+/// Render hot path highlighting.
+fn render_hot_paths(graph: &CallGraph, visit_counts: &HashMap<String, usize>, verbose: bool) {
+    println!(
+        "\n{}",
+        "── Hot Paths ─────────────────────────────────────────"
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Hot paths: greedily follow the highest-visit-count callee from each entry point.",
+            "This traces the most likely execution path through the call graph.",
+            "Arrow chain: entry → most visited callee → its most visited callee → ...",
+            "Color: white = entry, red/bold = hot (>50% of max visits), yellow = warm (>20%),",
+            "  plain = moderate, dim = cold. (depth N) = total chain length.",
+        ]);
+    }
+
+    if graph.entry_points.is_empty() {
+        println!("  {}", "No entry points found.".dimmed());
+        return;
+    }
+
+    for entry in &graph.entry_points {
+        let path = find_hot_path(graph, entry, visit_counts);
+        if path.len() <= 1 {
+            println!(
+                "\n  {} → {}",
+                entry.bold().bright_white(),
+                "(no callees)".dimmed()
+            );
+            continue;
+        }
+
+        println!();
+        print!("  ");
+        for (i, node) in path.iter().enumerate() {
+            let count = visit_counts.get(node).copied().unwrap_or(0);
+            let colored_name = if i == 0 {
+                node.bold().bright_white().to_string()
+            } else if count > 0 {
+                let max_count = visit_counts.values().max().copied().unwrap_or(1);
+                let heat = count as f64 / max_count as f64;
+                if heat > 0.5 {
+                    node.red().bold().to_string()
+                } else if heat > 0.2 {
+                    node.yellow().to_string()
+                } else {
+                    node.to_string()
+                }
+            } else {
+                node.dimmed().to_string()
+            };
+
+            if i > 0 {
+                print!(" → ");
+            }
+            print!("{}", colored_name);
+        }
+        println!("  (depth {})", path.len());
+    }
+}
+
+/// Render cold function detection.
+fn render_cold_functions(graph: &CallGraph, visit_counts: &HashMap<String, usize>, verbose: bool) {
+    let reachable = reachable_from_entries(graph);
+
+    let cold: Vec<&String> = graph
+        .functions
+        .iter()
+        .filter(|f| !visit_counts.contains_key(*f) && !reachable.contains(*f))
+        .collect();
+
+    println!(
+        "\n{}",
+        "── Cold Functions (Unreachable) ──────────────────────"
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Functions never reached from any entry point via call graph traversal.",
+            "These are dead code candidates — they exist in the source but no entry point",
+            "(main, #[test]) can reach them through any chain of calls.",
+            "Note: static analysis may miss dynamic dispatch or macro-generated calls.",
+        ]);
+    }
+
+    if cold.is_empty() {
+        println!(
+            "  {}",
+            "All functions are reachable from entry points.".green()
+        );
+    } else {
+        println!(
+            "\n  {} functions never reached from any entry point (dead code candidates):\n",
+            format!("{}", cold.len()).red().bold(),
+        );
+        for (i, name) in cold.iter().enumerate() {
+            if i >= 20 {
+                println!("  {}", format!("… +{} more", cold.len() - 20).dimmed());
+                break;
+            }
+            println!("  {} {}", "•".red(), name.dimmed());
+        }
+    }
+
+    println!();
+}
+
+/// Compact static entrypoint-reachability data for embedding in the dashboard.
+pub struct EntrypointReachabilitySummary {
+    /// Percentage of functions statically reachable from entry points.
+    pub reachable_pct: f64,
+    /// Total function count.
+    pub total_functions: usize,
+    /// Number of reachable functions.
+    pub reachable_count: usize,
+    /// Number of cold (unreachable) functions.
+    pub cold_count: usize,
+}
+
+/// Compute compact static entrypoint reachability for dashboard use.
+pub fn entrypoint_reachability_summary(
+    rs_files: &[PathBuf],
+    project_path: &Path,
+) -> Option<EntrypointReachabilitySummary> {
+    let graph = build_call_graph(rs_files, project_path);
+    if graph.functions.is_empty() {
+        return None;
+    }
+    let total_functions = graph.functions.len();
+    let reachable = reachable_from_entries(&graph);
+    let reachable_count = reachable.len();
+    let cold_count = total_functions.saturating_sub(reachable_count);
+    let reachable_pct = reachable_count as f64 / total_functions.max(1) as f64 * 100.0;
+
+    Some(EntrypointReachabilitySummary {
+        reachable_pct,
+        total_functions,
+        reachable_count,
+        cold_count,
+    })
+}
+
+/// Public entry point: render the datapaths subcommand.
+pub fn render_datapaths(
+    rs_files: &[PathBuf],
+    project_path: &Path,
+    num_walks: usize,
+    from_fn: Option<&str>,
+    verbose: bool,
+) {
+    let graph = build_call_graph(rs_files, project_path);
+
+    if graph.functions.is_empty() {
+        println!("{}", "No functions found to analyze.".yellow());
+        return;
+    }
+
+    let total_functions = graph.functions.len();
+
+    // Determine entry points
+    let entries: Vec<String> = if let Some(f) = from_fn {
+        // Check if the function exists (exact or suffix match)
+        let matched = graph
+            .functions
+            .iter()
+            .find(|name| *name == f || name.ends_with(&format!("::{}", f)));
+        match matched {
+            Some(m) => vec![m.clone()],
+            None => {
+                eprintln!(
+                    "{} Function '{}' not found in call graph.",
+                    "Error:".red().bold(),
+                    f
+                );
+                eprintln!("Available functions:");
+                for func in graph.functions.iter().take(20) {
+                    eprintln!("  {}", func);
+                }
+                if graph.functions.len() > 20 {
+                    eprintln!("  … +{} more", graph.functions.len() - 20);
+                }
+                return;
+            }
+        }
+    } else {
+        if graph.entry_points.is_empty() {
+            println!(
+                "{} No entry points (main or #[test]) found. Use --from to specify a start function.",
+                "Warning:".yellow().bold()
+            );
+            return;
+        }
+        graph.entry_points.clone()
+    };
+
+    println!(
+        "\n{}",
+        "══ Execution Flow Heatmap ═══════════════════════════════"
+            .bright_cyan()
+            .bold()
+    );
+    println!(
+        "  {} random walks from {} entry point(s)",
+        format!("{}", num_walks).bold(),
+        entries.len(),
+    );
+
+    // Run global simulation
+    let visit_counts = simulate_walks(&graph, &entries, num_walks);
+
+    // Render sections
+    render_heatmap(&visit_counts, total_functions, verbose);
+    render_per_entry(&graph, num_walks, verbose);
+    render_hot_paths(&graph, &visit_counts, verbose);
+    render_cold_functions(&graph, &visit_counts, verbose);
+}
+
+#[derive(Serialize)]
+struct VisitCountJson {
+    function: String,
+    visits: usize,
+    percentage: f64,
+}
+
+#[derive(Serialize)]
+struct DatapathsJson {
+    cstat_version: String,
+    visit_counts: Vec<VisitCountJson>,
+    coverage_percentage: f64,
+    hot_paths: Vec<Vec<String>>,
+    cold_functions: Vec<String>,
+    total_functions: usize,
+    total_visits: usize,
+}
+
+/// Render datapaths analysis as JSON.
+pub fn render_datapaths_json(
+    rs_files: &[PathBuf],
+    project_path: &Path,
+    num_walks: usize,
+    from_fn: Option<&str>,
+) {
+    let graph = build_call_graph(rs_files, project_path);
+    let total_functions = graph.functions.len();
+
+    let entries: Vec<String> = if let Some(f) = from_fn {
+        let matched = graph
+            .functions
+            .iter()
+            .find(|name| *name == f || name.ends_with(&format!("::{}", f)));
+        match matched {
+            Some(m) => vec![m.clone()],
+            None => vec![],
+        }
+    } else {
+        graph.entry_points.clone()
+    };
+
+    let visit_counts = simulate_walks(&graph, &entries, num_walks);
+    let total_visits: usize = visit_counts.values().sum();
+
+    let mut ranked: Vec<(&String, &usize)> = visit_counts.iter().collect();
+    ranked.sort_by(|a, b| b.1.cmp(a.1));
+
+    let visit_counts_json: Vec<VisitCountJson> = ranked
+        .iter()
+        .map(|(name, count)| VisitCountJson {
+            function: (*name).clone(),
+            visits: **count,
+            percentage: if total_visits > 0 {
+                **count as f64 / total_visits as f64 * 100.0
+            } else {
+                0.0
+            },
+        })
+        .collect();
+
+    let coverage = visit_counts.len() as f64 / total_functions.max(1) as f64 * 100.0;
+
+    let hot_paths: Vec<Vec<String>> = entries
+        .iter()
+        .map(|entry| find_hot_path(&graph, entry, &visit_counts))
+        .collect();
+
+    let reachable = reachable_from_entries(&graph);
+    let cold_functions: Vec<String> = graph
+        .functions
+        .iter()
+        .filter(|f| !visit_counts.contains_key(*f) && !reachable.contains(*f))
+        .cloned()
+        .collect();
+
+    let output = DatapathsJson {
+        cstat_version: env!("CARGO_PKG_VERSION").to_string(),
+        visit_counts: visit_counts_json,
+        coverage_percentage: coverage,
+        hot_paths,
+        cold_functions,
+        total_functions,
+        total_visits,
+    };
+
+    println!("{}", serde_json::to_string(&output).unwrap());
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/deps/mod.rs

@@ -113,57 +113,19 @@ fn collect_use_paths(tree: &syn::UseTree, prefix: &mut Vec<String>, results: &mu
     }
 }
 
-/// Match a use/mod path to a known project module name from a source-module context.
-fn resolve_to_module(
-    use_path: &str,
-    known_modules: &HashSet<String>,
-    current_module: &str,
-) -> Option<String> {
-    if use_path == "crate" {
-        return None;
-    }
-    if use_path == "self" {
-        return known_modules
-            .contains(current_module)
-            .then(|| current_module.to_string());
-    }
-    if use_path == "super" {
-        return parent_module(current_module)
-            .filter(|parent| known_modules.contains(*parent))
-            .map(ToString::to_string);
-    }
+/// Match a use path to a known project module name.
+fn resolve_to_module(use_path: &str, known_modules: &HashSet<String>) -> Option<String> {
+    let path = if let Some(rest) = use_path.strip_prefix("crate::") {
+        rest
+    } else if let Some(rest) = use_path.strip_prefix("self::") {
+        rest
+    } else if let Some(rest) = use_path.strip_prefix("super::") {
+        rest
+    } else {
+        use_path
+    };
 
-    if let Some(rest) = use_path.strip_prefix("crate::") {
-        return resolve_absolute_module_path(rest, known_modules);
-    }
-
-    if let Some(rest) = use_path.strip_prefix("self::") {
-        return resolve_relative_module_path(current_module, rest, known_modules).or_else(|| {
-            known_modules
-                .contains(current_module)
-                .then(|| current_module.to_string())
-        });
-    }
-
-    let mut base = current_module;
-    let mut rest = use_path;
-    let mut saw_super = false;
-    while let Some(stripped) = rest.strip_prefix("super::") {
-        saw_super = true;
-        base = parent_module(base).unwrap_or("");
-        rest = stripped;
-    }
-    if saw_super {
-        return resolve_relative_module_path(base, rest, known_modules)
-            .or_else(|| known_modules.contains(base).then(|| base.to_string()));
-    }
-
-    resolve_relative_module_path(current_module, use_path, known_modules)
-        .or_else(|| resolve_absolute_module_path(use_path, known_modules))
-}
-
-fn resolve_absolute_module_path(path: &str, known_modules: &HashSet<String>) -> Option<String> {
-    let parts: Vec<&str> = path.split("::").filter(|part| !part.is_empty()).collect();
+    let parts: Vec<&str> = path.split("::").collect();
     for len in (1..=parts.len()).rev() {
         let candidate = parts[..len].join("::");
         if known_modules.contains(&candidate) {
@@ -173,26 +135,6 @@ fn resolve_absolute_module_path(path: &str, known_modules: &HashSet<String>) ->
     None
 }
 
-fn resolve_relative_module_path(
-    base: &str,
-    path: &str,
-    known_modules: &HashSet<String>,
-) -> Option<String> {
-    if base.is_empty() {
-        return resolve_absolute_module_path(path, known_modules);
-    }
-    let absolute = if path.is_empty() {
-        base.to_string()
-    } else {
-        format!("{base}::{path}")
-    };
-    resolve_absolute_module_path(&absolute, known_modules)
-}
-
-fn parent_module(module: &str) -> Option<&str> {
-    module.rsplit_once("::").map(|(parent, _)| parent)
-}
-
 /// Compute coupling pairs from the edge set, sorted by strength descending.
 fn build_coupling_pairs(edges: &HashSet<DepEdge>) -> Vec<(String, String, usize)> {
     let mut coupling_pairs: Vec<(String, String, usize)> = Vec::new();
@@ -267,7 +209,7 @@ pub fn analyze_deps(rs_files: &[PathBuf], project_path: &Path) -> DepAnalysis {
         let mut seen_targets: HashSet<String> = HashSet::new();
 
         for target in &use_targets {
-            if let Some(to_module) = resolve_to_module(target, &known_modules, &from_module) {
+            if let Some(to_module) = resolve_to_module(target, &known_modules) {
                 if to_module != from_module && seen_targets.insert(to_module.clone()) {
                     let edge = DepEdge {
                         from: from_module.clone(),
@@ -318,7 +260,7 @@ pub fn analyze_file_deps(
     let mut internal = Vec::new();
     let mut external = Vec::new();
     for raw in use_targets {
-        if let Some(resolved_module) = resolve_to_module(&raw, &known_modules, &module) {
+        if let Some(resolved_module) = resolve_to_module(&raw, &known_modules) {
             internal.push(FileDependency {
                 raw,
                 resolved_module: Some(resolved_module),
@@ -408,15 +350,7 @@ fn relative_path_string(project_path: &Path, path: &Path) -> String {
         .replace('\\', "/")
 }
 
-fn function_graph_name(file_module: &str, function_name: &str) -> String {
-    if file_module == "main" || file_module == "lib" {
-        function_name.to_string()
-    } else {
-        format!("{file_module}::{function_name}")
-    }
-}
-
-/// Compute call cohesion: fraction of source functions calling another function in the same module.
+/// Compute call cohesion: fraction of functions calling another function in the same module.
 fn compute_call_cohesion(
     module_functions: &HashMap<String, Vec<String>>,
     call_graph: &flow::CallGraph,
@@ -447,7 +381,7 @@ fn compute_call_cohesion(
     call_cohesion_map
 }
 
-/// Compute type cohesion: fraction of functions sharing signature type tokens within a module.
+/// Compute type cohesion: fraction of functions sharing parameter/return types within a module.
 fn compute_type_cohesion(
     module_func_infos: &HashMap<String, Vec<&ast_parser::FunctionInfo>>,
 ) -> HashMap<String, f64> {
@@ -460,7 +394,7 @@ fn compute_type_cohesion(
 
         let func_types: Vec<HashSet<String>> = funcs
             .iter()
-            .map(|f| extract_signature_types(&f.file, f.line_start, f.line_end))
+            .map(|f| extract_param_types(&f.file, f.line_start, f.line_end))
             .collect();
 
         let mut sharing_count = 0usize;
@@ -481,20 +415,30 @@ fn compute_type_cohesion(
     type_cohesion_map
 }
 
-/// Compute per-source-module cohesion metrics.
+/// Compute per-module cohesion metrics.
 pub fn compute_cohesion(rs_files: &[PathBuf], project_path: &Path) -> Vec<ModuleCohesion> {
     let call_graph = flow::build_call_graph(rs_files, project_path);
     let symbols = ast_parser::parse_project(rs_files);
 
     let mut module_functions: HashMap<String, Vec<String>> = HashMap::new();
+    for func_name in &call_graph.functions {
+        let module = if let Some(pos) = func_name.rfind("::") {
+            func_name[..pos].to_string()
+        } else {
+            "main".to_string()
+        };
+        module_functions
+            .entry(module)
+            .or_default()
+            .push(func_name.clone());
+    }
+
+    let call_cohesion_map = compute_call_cohesion(&module_functions, &call_graph);
+
     let mut module_func_infos: HashMap<String, Vec<&ast_parser::FunctionInfo>> = HashMap::new();
     for file_syms in &symbols.files {
         let module_name = crate_render::module_name_from_path(&file_syms.path, project_path);
         for func in &file_syms.functions {
-            module_functions
-                .entry(module_name.clone())
-                .or_default()
-                .push(function_graph_name(&module_name, &func.name));
             module_func_infos
                 .entry(module_name.clone())
                 .or_default()
@@ -502,21 +446,31 @@ pub fn compute_cohesion(rs_files: &[PathBuf], project_path: &Path) -> Vec<Module
         }
     }
 
-    let call_cohesion_map = compute_call_cohesion(&module_functions, &call_graph);
     let type_cohesion_map = compute_type_cohesion(&module_func_infos);
 
-    let mut results: Vec<ModuleCohesion> = module_func_infos
+    let all_modules: HashSet<&str> = module_functions
+        .keys()
+        .map(|s| s.as_str())
+        .chain(module_func_infos.keys().map(|s| s.as_str()))
+        .collect();
+
+    let mut results: Vec<ModuleCohesion> = all_modules
         .iter()
-        .map(|(module, funcs)| {
+        .map(|&module| {
             let call_c = call_cohesion_map.get(module).copied().unwrap_or(0.0);
             let type_c = type_cohesion_map.get(module).copied().unwrap_or(0.0);
+            let func_count = module_functions
+                .get(module)
+                .map(|v| v.len())
+                .or_else(|| module_func_infos.get(module).map(|v| v.len()))
+                .unwrap_or(0);
             let combined = (0.6 * call_c + 0.4 * type_c).clamp(0.0, 1.0);
             ModuleCohesion {
-                module: module.clone(),
+                module: module.to_string(),
                 call_cohesion: call_c,
                 type_cohesion: type_c,
                 combined,
-                function_count: funcs.len(),
+                function_count: func_count,
             }
         })
         .collect();
@@ -525,13 +479,12 @@ pub fn compute_cohesion(rs_files: &[PathBuf], project_path: &Path) -> Vec<Module
         a.combined
             .partial_cmp(&b.combined)
             .unwrap_or(std::cmp::Ordering::Equal)
-            .then_with(|| a.module.cmp(&b.module))
     });
     results
 }
 
-/// Extract parameter/return type-like tokens from a function signature in a source file.
-fn extract_signature_types(file: &Path, line_start: usize, line_end: usize) -> HashSet<String> {
+/// Extract parameter/return type names from a function in a source file.
+fn extract_param_types(file: &Path, line_start: usize, line_end: usize) -> HashSet<String> {
     let content = match std::fs::read_to_string(file) {
         Ok(c) => c,
         Err(_) => return HashSet::new(),
@@ -539,14 +492,10 @@ fn extract_signature_types(file: &Path, line_start: usize, line_end: usize) -> H
     let lines: Vec<&str> = content.lines().collect();
     let start = line_start.saturating_sub(1);
     let end = line_end.min(lines.len());
-    let span_text: String = lines[start..end].join("\n");
-    let signature_text = span_text
-        .split_once('{')
-        .map(|(signature, _)| signature)
-        .unwrap_or(&span_text);
+    let sig_text: String = lines[start..end].join("\n");
 
     let mut types = HashSet::new();
-    for token in signature_text.split(|c: char| !c.is_alphanumeric() && c != '_') {
+    for token in sig_text.split(|c: char| !c.is_alphanumeric() && c != '_') {
         let t = token.trim();
         if t.is_empty() || t.len() < 2 {
             continue;

src/deps/render.rs

@@ -26,7 +26,6 @@ struct CouplingPairJson {
     module_b: String,
     strength: usize,
     direction: String,
-    edges: Vec<DepEdgeJson>,
 }
 
 #[derive(Serialize)]
@@ -117,7 +116,7 @@ fn render_matrix_rows(
 fn render_matrix_legend(display_modules: &[&String]) {
     println!();
     println!(
-        "  {} no dependency  {} one-way pair  {} bidirectional pair",
+        "  {} no dependency  {} unidirectional  {} bidirectional",
         "0".dimmed(),
         "1".yellow(),
         "2".red().bold(),
@@ -139,14 +138,13 @@ fn render_dependency_matrix(analysis: &DepAnalysis, top_n: usize, term_w: usize,
 
     if verbose {
         render::verbose_block(&[
-            "Matrix showing coupling strength between module pairs.",
-            "Cells are pair strength, not edge direction: 0 = no dependency,",
-            "  1 = exactly one direction exists, 2 = both modules import each other.",
+            "Matrix showing coupling intensity between module pairs.",
+            "Cell [row, col] = 0 (dim, no dependency), 1 (yellow, unidirectional),",
+            "  2 (red/bold, bidirectional — both modules import each other).",
             "Diagonal is marked '·' (a module cannot depend on itself).",
             "Modules are sorted by total connectivity (in + out degree).",
             "Row/column indices map to module names shown in the legend below the matrix.",
-            "Use Coupling Ranking or JSON edges for source -> target direction.",
-            "Built from top-level source 'use' and external 'mod' statements parsed from each file.",
+            "Built from 'use' and 'mod' statements found by parsing each file's AST.",
         ]);
         render::guide_ref("modularity");
     }
@@ -206,9 +204,9 @@ fn render_coupling_ranking(analysis: &DepAnalysis, top_n: usize, verbose: bool)
     if verbose {
         render::verbose_block(&[
             "Module pairs ranked by coupling strength.",
-            "One-way rows show actual source module -> target module direction.",
             "◆ bidirectional (red) = both modules import each other. This is a coupling risk —",
             "  changes in either module may ripple to the other.",
+            "→ unidirectional (yellow) = one-way dependency, lower risk.",
             "Pairs are sorted by coupling strength descending, then alphabetically.",
         ]);
     }
@@ -219,52 +217,37 @@ fn render_coupling_ranking(analysis: &DepAnalysis, top_n: usize, verbose: bool)
     }
 
     let display_count = analysis.coupling_pairs.len().min(top_n);
-    let edge_set: HashSet<(&str, &str)> = analysis
-        .edges
-        .iter()
-        .map(|edge| (edge.from.as_str(), edge.to.as_str()))
-        .collect();
     println!(
         "\n  {:<30} {:<30} {}",
-        "From".bold().underline(),
-        "To".bold().underline(),
+        "Module A".bold().underline(),
+        "Module B".bold().underline(),
         "Coupling".bold().underline(),
     );
 
     for (a, b, strength) in analysis.coupling_pairs.iter().take(display_count) {
-        let a_to_b = edge_set.contains(&(a.as_str(), b.as_str()));
-        let b_to_a = edge_set.contains(&(b.as_str(), a.as_str()));
-        let (from, to, coupling_label) = if a_to_b && b_to_a {
-            (
-                a.as_str(),
-                b.as_str(),
-                "◆ bidirectional".red().bold().to_string(),
-            )
-        } else if a_to_b {
-            (a.as_str(), b.as_str(), "→ one-way".yellow().to_string())
+        let coupling_label = if *strength >= 2 {
+            "◆ bidirectional".red().bold().to_string()
         } else {
-            (b.as_str(), a.as_str(), "→ one-way".yellow().to_string())
+            "→ unidirectional".yellow().to_string()
         };
 
-        let from_display = if from.len() > 28 {
-            format!("..{}", &from[from.len() - 26..])
+        let a_display = if a.len() > 28 {
+            format!("..{}", &a[a.len() - 26..])
         } else {
-            from.to_string()
+            a.clone()
         };
-        let to_display = if to.len() > 28 {
-            format!("..{}", &to[to.len() - 26..])
+        let b_display = if b.len() > 28 {
+            format!("..{}", &b[b.len() - 26..])
         } else {
-            to.to_string()
+            b.clone()
         };
 
         println!(
             "  {:<30} {:<30} {}",
-            from_display.dimmed(),
-            to_display.dimmed(),
+            a_display.dimmed(),
+            b_display.dimmed(),
             coupling_label
         );
-
-        let _ = strength;
     }
 
     if analysis.coupling_pairs.len() > display_count {
@@ -420,11 +403,11 @@ fn render_cohesion_section(cohesion: &[ModuleCohesion], top_n: usize, verbose: b
 
     if verbose {
         render::verbose_block(&[
-            "Per-source-module cohesion scores measuring internal focus/coherence.",
-            "Call cohesion: fraction of parsed source functions calling another function in the same source module.",
-            "Type cohesion: fraction of parsed source functions sharing signature type tokens within the module.",
+            "Per-module cohesion scores measuring internal focus/coherence.",
+            "Call cohesion: fraction of functions calling another function in the same module.",
+            "Type cohesion: fraction of functions sharing parameter/return types within the module.",
             "Combined: weighted average (60% call + 40% type), 0.0–1.0 where higher = more cohesive.",
-            "Low cohesion suggests the source module bundles unrelated functionality.",
+            "Low cohesion suggests the module bundles unrelated functionality.",
             "Modules sorted by combined cohesion ascending (least cohesive first).",
         ]);
     }
@@ -522,39 +505,18 @@ pub fn render_deps_json(rs_files: &[PathBuf], project_path: &Path) {
         })
         .collect();
 
-    let edge_set: HashSet<(&str, &str)> = analysis
-        .edges
-        .iter()
-        .map(|edge| (edge.from.as_str(), edge.to.as_str()))
-        .collect();
     let coupling_pairs: Vec<CouplingPairJson> = analysis
         .coupling_pairs
         .iter()
-        .map(|(a, b, s)| {
-            let mut pair_edges = Vec::new();
-            if edge_set.contains(&(a.as_str(), b.as_str())) {
-                pair_edges.push(DepEdgeJson {
-                    from: a.clone(),
-                    to: b.clone(),
-                });
-            }
-            if edge_set.contains(&(b.as_str(), a.as_str())) {
-                pair_edges.push(DepEdgeJson {
-                    from: b.clone(),
-                    to: a.clone(),
-                });
-            }
-            CouplingPairJson {
-                module_a: a.clone(),
-                module_b: b.clone(),
-                strength: *s,
-                direction: if *s >= 2 {
-                    "bidirectional".to_string()
-                } else {
-                    "unidirectional".to_string()
-                },
-                edges: pair_edges,
-            }
+        .map(|(a, b, s)| CouplingPairJson {
+            module_a: a.clone(),
+            module_b: b.clone(),
+            strength: *s,
+            direction: if *s >= 2 {
+                "bidirectional".to_string()
+            } else {
+                "unidirectional".to_string()
+            },
         })
         .collect();
 

src/diagnostics/mod.rs

@@ -0,0 +1,699 @@
+mod scoring;
+
+use serde::Serialize;
+use std::collections::{HashMap, HashSet};
+use std::path::{Path, PathBuf};
+
+use crate::ast_parser;
+use crate::complexity;
+use crate::deps;
+use crate::flow;
+use crate::loc;
+use crate::redundancy;
+
+// ── Diagnostic types ─────────────────────────────────────────────
+
+#[derive(Debug, Clone, Serialize)]
+pub struct Diagnostic {
+    pub severity: Severity,
+    pub category: Category,
+    pub location: Location,
+    pub metric: f64,
+    pub threshold: f64,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub context: Option<serde_json::Value>,
+    pub message: String,
+}
+
+#[derive(Debug, Clone, Serialize, PartialEq, Eq, PartialOrd, Ord)]
+#[serde(rename_all = "snake_case")]
+pub enum Severity {
+    Warn,
+    Alert,
+}
+
+#[derive(Debug, Clone, Serialize, PartialEq, Eq)]
+#[serde(rename_all = "snake_case")]
+pub enum Category {
+    BloatedFile,
+    BloatedFunction,
+    HighComplexity,
+    HighCognitive,
+    DeepNesting,
+    HighCoupling,
+    GodModule,
+    DeadCode,
+    LowCohesion,
+    RedundantCode,
+    TooManyParams,
+    CyclicDeps,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct Location {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub file: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub function: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub module: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub line_start: Option<usize>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub line_end: Option<usize>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct HealthScores {
+    pub modularity: f64,
+    pub complexity: f64,
+    pub maintainability: f64,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct DiagnosticReport {
+    pub diagnostics: Vec<Diagnostic>,
+    pub scores: HealthScores,
+}
+
+// ── Thresholds ───────────────────────────────────────────────────
+
+pub(crate) struct Threshold {
+    pub(crate) warn: f64,
+    pub(crate) alert: f64,
+}
+
+pub(crate) const FILE_LOC: Threshold = Threshold {
+    warn: 500.0,
+    alert: 800.0,
+};
+const FUNC_LOC: Threshold = Threshold {
+    warn: 50.0,
+    alert: 100.0,
+};
+pub(crate) const CYCLOMATIC: Threshold = Threshold {
+    warn: 10.0,
+    alert: 20.0,
+};
+pub(crate) const COGNITIVE: Threshold = Threshold {
+    warn: 15.0,
+    alert: 30.0,
+};
+const NESTING: Threshold = Threshold {
+    warn: 4.0,
+    alert: 6.0,
+};
+const PARAMS: Threshold = Threshold {
+    warn: 5.0,
+    alert: 8.0,
+};
+pub(crate) const REDUNDANCY: Threshold = Threshold {
+    warn: 0.7,
+    alert: 0.9,
+};
+pub(crate) const COHESION: Threshold = Threshold {
+    warn: 0.3,
+    alert: 0.1,
+};
+
+// ── Main analysis entry point (orchestrator) ─────────────────────
+
+pub fn run_diagnostics(rs_files: &[PathBuf], project_path: &Path) -> DiagnosticReport {
+    let mut diagnostics = Vec::new();
+
+    // --- LoC analysis ---
+    let (file_stats, _agg_loc) = loc::analyze_files(rs_files);
+
+    // --- Complexity analysis ---
+    let symbols = ast_parser::parse_project(rs_files);
+    let func_complexities = complexity::compute_all(&symbols, project_path);
+
+    // Build per-file function index for cross-referencing
+    let mut funcs_by_file: HashMap<String, Vec<&complexity::FunctionComplexity>> = HashMap::new();
+    for fc in &func_complexities {
+        funcs_by_file.entry(fc.file.clone()).or_default().push(fc);
+    }
+
+    diagnose_bloated_files(&file_stats, &funcs_by_file, project_path, &mut diagnostics);
+    diagnose_function_metrics(&func_complexities, &mut diagnostics);
+
+    // --- Dependency analysis ---
+    let dep_analysis = deps::analyze_deps(rs_files, project_path);
+
+    diagnose_coupling(&dep_analysis, &mut diagnostics);
+    diagnose_god_modules(&dep_analysis, &mut diagnostics);
+
+    // --- Dead code (cold functions) ---
+    let call_graph = flow::build_call_graph(rs_files, project_path);
+    let reachable = compute_reachable(&call_graph);
+    diagnose_dead_code(&call_graph, &reachable, &mut diagnostics);
+
+    diagnose_cyclic_deps(&dep_analysis, &mut diagnostics);
+
+    // --- Redundancy ---
+    let redundant_pairs = redundancy::detect_redundancy(rs_files, project_path);
+    diagnose_redundancy(&redundant_pairs, &mut diagnostics);
+
+    // --- Low cohesion ---
+    let cohesion_data = deps::compute_cohesion(rs_files, project_path);
+    diagnose_low_cohesion(&cohesion_data, &mut diagnostics);
+
+    // --- Sort diagnostics: alerts first, then by metric magnitude descending ---
+    diagnostics.sort_by(|a, b| {
+        a.severity.cmp(&b.severity).then_with(|| {
+            b.metric
+                .partial_cmp(&a.metric)
+                .unwrap_or(std::cmp::Ordering::Equal)
+        })
+    });
+
+    // --- Compute health scores ---
+    let scores = scoring::compute_health_scores(
+        &file_stats,
+        &func_complexities,
+        &dep_analysis,
+        &redundant_pairs,
+        &call_graph,
+        &reachable,
+        rs_files,
+        project_path,
+    );
+
+    DiagnosticReport {
+        diagnostics,
+        scores,
+    }
+}
+
+// ── Extracted diagnostic helpers ────────────────────────────────
+
+fn diagnose_bloated_files(
+    file_stats: &[loc::FileLocStats],
+    funcs_by_file: &HashMap<String, Vec<&complexity::FunctionComplexity>>,
+    project_path: &Path,
+    diagnostics: &mut Vec<Diagnostic>,
+) {
+    for stat in file_stats {
+        let loc = stat.code_lines as f64;
+        let rel_path = stat
+            .path
+            .strip_prefix(project_path)
+            .unwrap_or(&stat.path)
+            .display()
+            .to_string();
+
+        let (sev, thresh) = if loc > FILE_LOC.alert {
+            (Some(Severity::Alert), FILE_LOC.alert)
+        } else if loc > FILE_LOC.warn {
+            (Some(Severity::Warn), FILE_LOC.warn)
+        } else {
+            (None, 0.0)
+        };
+
+        if let Some(severity) = sev {
+            let file_funcs = funcs_by_file.get(rel_path.as_str());
+            let func_count = file_funcs.map(|v| v.len()).unwrap_or(0);
+            let top_complex: Vec<serde_json::Value> = file_funcs
+                .map(|fns| {
+                    let mut sorted: Vec<_> = fns.iter().collect();
+                    sorted.sort_by(|a, b| {
+                        b.composite_score
+                            .partial_cmp(&a.composite_score)
+                            .unwrap_or(std::cmp::Ordering::Equal)
+                    });
+                    sorted
+                        .into_iter()
+                        .take(3)
+                        .map(|f| {
+                            serde_json::json!({
+                                "name": f.name,
+                                "composite_score": f.composite_score,
+                                "lines": f.line_count
+                            })
+                        })
+                        .collect()
+                })
+                .unwrap_or_default();
+
+            let ctx = serde_json::json!({
+                "function_count": func_count,
+                "top_complex_functions": top_complex,
+            });
+
+            let msg = format!(
+                "{} is {} lines with {} functions",
+                rel_path, stat.code_lines, func_count
+            );
+
+            diagnostics.push(Diagnostic {
+                severity,
+                category: Category::BloatedFile,
+                location: Location {
+                    file: Some(rel_path.clone()),
+                    function: None,
+                    module: None,
+                    line_start: None,
+                    line_end: None,
+                },
+                metric: loc,
+                threshold: thresh,
+                context: Some(ctx),
+                message: msg,
+            });
+        }
+    }
+}
+
+fn diagnose_function_metrics(
+    func_complexities: &[complexity::FunctionComplexity],
+    diagnostics: &mut Vec<Diagnostic>,
+) {
+    for fc in func_complexities {
+        diagnose_fn_complexity(fc, diagnostics);
+        diagnose_fn_structure(fc, diagnostics);
+    }
+}
+
+fn diagnose_fn_complexity(fc: &complexity::FunctionComplexity, diagnostics: &mut Vec<Diagnostic>) {
+    let line_count = fc.line_count as f64;
+    let cyc = fc.cyclomatic as f64;
+    let cog = fc.cognitive as f64;
+
+    // Bloated function
+    if let Some((sev, thresh)) = check_threshold(line_count, &FUNC_LOC) {
+        let ctx = serde_json::json!({
+            "cyclomatic": fc.cyclomatic,
+            "cognitive": fc.cognitive,
+            "nesting_depth": fc.nesting_depth,
+            "composite_score": fc.composite_score,
+        });
+        let msg = format!(
+            "{} is {} lines (cyclomatic {}, cognitive {})",
+            fc.name, fc.line_count, fc.cyclomatic, fc.cognitive
+        );
+        diagnostics.push(Diagnostic {
+            severity: sev,
+            category: Category::BloatedFunction,
+            location: fn_location(&fc.name, &fc.file),
+            metric: line_count,
+            threshold: thresh,
+            context: Some(ctx),
+            message: msg,
+        });
+    }
+
+    // Cyclomatic complexity
+    if let Some((sev, thresh)) = check_threshold(cyc, &CYCLOMATIC) {
+        let ctx = serde_json::json!({
+            "cognitive": fc.cognitive,
+            "nesting_depth": fc.nesting_depth,
+            "line_count": fc.line_count,
+        });
+        let msg = format!(
+            "{} has cyclomatic complexity {} ({} lines, nesting depth {})",
+            fc.name, fc.cyclomatic, fc.line_count, fc.nesting_depth
+        );
+        diagnostics.push(Diagnostic {
+            severity: sev,
+            category: Category::HighComplexity,
+            location: fn_location(&fc.name, &fc.file),
+            metric: cyc,
+            threshold: thresh,
+            context: Some(ctx),
+            message: msg,
+        });
+    }
+
+    // Cognitive complexity
+    if let Some((sev, thresh)) = check_threshold(cog, &COGNITIVE) {
+        let ctx = serde_json::json!({
+            "cyclomatic": fc.cyclomatic,
+            "nesting_depth": fc.nesting_depth,
+            "line_count": fc.line_count,
+        });
+        let msg = format!(
+            "{} has cognitive complexity {} (cyclomatic {}, nesting depth {})",
+            fc.name, fc.cognitive, fc.cyclomatic, fc.nesting_depth
+        );
+        diagnostics.push(Diagnostic {
+            severity: sev,
+            category: Category::HighCognitive,
+            location: fn_location(&fc.name, &fc.file),
+            metric: cog,
+            threshold: thresh,
+            context: Some(ctx),
+            message: msg,
+        });
+    }
+}
+
+fn diagnose_fn_structure(fc: &complexity::FunctionComplexity, diagnostics: &mut Vec<Diagnostic>) {
+    let nest = fc.nesting_depth as f64;
+    let params = fc.param_count as f64;
+
+    // Deep nesting
+    if let Some((sev, thresh)) = check_threshold(nest, &NESTING) {
+        let ctx = serde_json::json!({
+            "cyclomatic": fc.cyclomatic,
+            "cognitive": fc.cognitive,
+            "line_count": fc.line_count,
+        });
+        let msg = format!(
+            "{} has nesting depth {} (cyclomatic {}, {} lines)",
+            fc.name, fc.nesting_depth, fc.cyclomatic, fc.line_count
+        );
+        diagnostics.push(Diagnostic {
+            severity: sev,
+            category: Category::DeepNesting,
+            location: fn_location(&fc.name, &fc.file),
+            metric: nest,
+            threshold: thresh,
+            context: Some(ctx),
+            message: msg,
+        });
+    }
+
+    // Too many params
+    if let Some((sev, thresh)) = check_threshold(params, &PARAMS) {
+        let ctx = serde_json::json!({
+            "line_count": fc.line_count,
+            "cyclomatic": fc.cyclomatic,
+        });
+        let msg = format!(
+            "{} takes {} parameters ({} lines, cyclomatic {})",
+            fc.name, fc.param_count, fc.line_count, fc.cyclomatic
+        );
+        diagnostics.push(Diagnostic {
+            severity: sev,
+            category: Category::TooManyParams,
+            location: fn_location(&fc.name, &fc.file),
+            metric: params,
+            threshold: thresh,
+            context: Some(ctx),
+            message: msg,
+        });
+    }
+}
+
+fn diagnose_coupling(dep_analysis: &deps::DepAnalysis, diagnostics: &mut Vec<Diagnostic>) {
+    for (a, b, strength) in &dep_analysis.coupling_pairs {
+        if *strength >= 2 {
+            let fan_in_a = dep_analysis.in_degree.get(a).copied().unwrap_or(0);
+            let fan_out_a = dep_analysis.out_degree.get(a).copied().unwrap_or(0);
+            let fan_in_b = dep_analysis.in_degree.get(b).copied().unwrap_or(0);
+            let fan_out_b = dep_analysis.out_degree.get(b).copied().unwrap_or(0);
+            let ctx = serde_json::json!({
+                "module_a": { "fan_in": fan_in_a, "fan_out": fan_out_a },
+                "module_b": { "fan_in": fan_in_b, "fan_out": fan_out_b },
+            });
+            diagnostics.push(Diagnostic {
+                severity: Severity::Warn,
+                category: Category::HighCoupling,
+                location: Location {
+                    file: None,
+                    function: None,
+                    module: Some(format!("{} <-> {}", a, b)),
+                    line_start: None,
+                    line_end: None,
+                },
+                metric: *strength as f64,
+                threshold: 2.0,
+                context: Some(ctx),
+                message: format!(
+                    "{} and {} have bidirectional dependency (strength {})",
+                    a, b, strength
+                ),
+            });
+        }
+    }
+}
+
+fn diagnose_god_modules(dep_analysis: &deps::DepAnalysis, diagnostics: &mut Vec<Diagnostic>) {
+    let fan_totals: Vec<f64> = dep_analysis
+        .modules
+        .iter()
+        .map(|m| {
+            let in_d = dep_analysis.in_degree.get(m).copied().unwrap_or(0);
+            let out_d = dep_analysis.out_degree.get(m).copied().unwrap_or(0);
+            (in_d + out_d) as f64
+        })
+        .collect();
+
+    if fan_totals.is_empty() {
+        return;
+    }
+
+    let mean_fan = fan_totals.iter().sum::<f64>() / fan_totals.len() as f64;
+    let var_fan = fan_totals
+        .iter()
+        .map(|v| (v - mean_fan).powi(2))
+        .sum::<f64>()
+        / fan_totals.len() as f64;
+    let std_fan = var_fan.sqrt();
+    let warn_thresh = mean_fan + std_fan;
+    let alert_thresh = mean_fan + 2.0 * std_fan;
+
+    for (i, m) in dep_analysis.modules.iter().enumerate() {
+        let total = fan_totals[i];
+        let in_d = dep_analysis.in_degree.get(m).copied().unwrap_or(0);
+        let out_d = dep_analysis.out_degree.get(m).copied().unwrap_or(0);
+
+        if total > alert_thresh && alert_thresh > 0.0 {
+            let ctx = serde_json::json!({
+                "fan_in": in_d,
+                "fan_out": out_d,
+                "mean": mean_fan,
+                "stddev": std_fan,
+            });
+            diagnostics.push(Diagnostic {
+                severity: Severity::Alert,
+                category: Category::GodModule,
+                location: mod_location(m),
+                metric: total,
+                threshold: alert_thresh,
+                context: Some(ctx),
+                message: format!(
+                    "{} has fan-in+fan-out of {} (mean+2σ={:.1}, fan-in {}, fan-out {})",
+                    m, total as usize, alert_thresh, in_d, out_d
+                ),
+            });
+        } else if total > warn_thresh && warn_thresh > 0.0 {
+            let ctx = serde_json::json!({
+                "fan_in": in_d,
+                "fan_out": out_d,
+                "mean": mean_fan,
+                "stddev": std_fan,
+            });
+            diagnostics.push(Diagnostic {
+                severity: Severity::Warn,
+                category: Category::GodModule,
+                location: mod_location(m),
+                metric: total,
+                threshold: warn_thresh,
+                context: Some(ctx),
+                message: format!(
+                    "{} has fan-in+fan-out of {} (mean+1σ={:.1}, fan-in {}, fan-out {})",
+                    m, total as usize, warn_thresh, in_d, out_d
+                ),
+            });
+        }
+    }
+}
+
+fn compute_reachable(call_graph: &flow::CallGraph) -> HashSet<String> {
+    let mut reachable = HashSet::new();
+    let mut queue: Vec<String> = call_graph.entry_points.clone();
+    while let Some(node) = queue.pop() {
+        if !reachable.insert(node.clone()) {
+            continue;
+        }
+        if let Some(callees) = call_graph.adjacency.get(&node) {
+            for callee in callees {
+                if !reachable.contains(callee) {
+                    queue.push(callee.clone());
+                }
+            }
+        }
+    }
+    reachable
+}
+
+fn diagnose_dead_code(
+    call_graph: &flow::CallGraph,
+    reachable: &HashSet<String>,
+    diagnostics: &mut Vec<Diagnostic>,
+) {
+    for func in &call_graph.functions {
+        if !reachable.contains(func) {
+            diagnostics.push(Diagnostic {
+                severity: Severity::Warn,
+                category: Category::DeadCode,
+                location: Location {
+                    file: None,
+                    function: Some(func.clone()),
+                    module: None,
+                    line_start: None,
+                    line_end: None,
+                },
+                metric: 0.0,
+                threshold: 0.0,
+                context: None,
+                message: format!("{} is not reachable from any entry point", func),
+            });
+        }
+    }
+}
+
+fn diagnose_cyclic_deps(dep_analysis: &deps::DepAnalysis, diagnostics: &mut Vec<Diagnostic>) {
+    let mut adj: HashMap<String, Vec<String>> = HashMap::new();
+    for m in &dep_analysis.modules {
+        adj.entry(m.clone()).or_default();
+    }
+    for edge in &dep_analysis.edges {
+        adj.entry(edge.from.clone())
+            .or_default()
+            .push(edge.to.clone());
+    }
+
+    let sccs = scoring::tarjan_scc_simple(&dep_analysis.modules, &adj);
+    for scc in &sccs {
+        if scc.len() > 1 {
+            let members = scc.join(", ");
+            let ctx = serde_json::json!({
+                "members": scc,
+                "member_count": scc.len(),
+            });
+            diagnostics.push(Diagnostic {
+                severity: Severity::Warn,
+                category: Category::CyclicDeps,
+                location: Location {
+                    file: None,
+                    function: None,
+                    module: Some(members.clone()),
+                    line_start: None,
+                    line_end: None,
+                },
+                metric: scc.len() as f64,
+                threshold: 1.0,
+                context: Some(ctx),
+                message: format!("Cyclic dependency among {} modules: {}", scc.len(), members),
+            });
+        }
+    }
+}
+
+fn diagnose_redundancy(
+    redundant_pairs: &[redundancy::RedundantPair],
+    diagnostics: &mut Vec<Diagnostic>,
+) {
+    for pair in redundant_pairs {
+        let (sev, thresh) = if pair.similarity > REDUNDANCY.alert {
+            (Some(Severity::Alert), REDUNDANCY.alert)
+        } else if pair.similarity > REDUNDANCY.warn {
+            (Some(Severity::Warn), REDUNDANCY.warn)
+        } else {
+            (None, 0.0)
+        };
+
+        if let Some(severity) = sev {
+            let ctx = serde_json::json!({
+                "func_a": pair.func_a,
+                "func_b": pair.func_b,
+                "file_a": pair.file_a,
+                "file_b": pair.file_b,
+                "kind": pair.kind.to_string(),
+            });
+            let msg = format!(
+                "{} and {} have {:.0}% similarity ({})",
+                pair.func_a,
+                pair.func_b,
+                pair.similarity * 100.0,
+                pair.kind
+            );
+            diagnostics.push(Diagnostic {
+                severity,
+                category: Category::RedundantCode,
+                location: Location {
+                    file: Some(pair.file_a.clone()),
+                    function: Some(format!("{} / {}", pair.func_a, pair.func_b)),
+                    module: None,
+                    line_start: Some(pair.line_a),
+                    line_end: None,
+                },
+                metric: pair.similarity,
+                threshold: thresh,
+                context: Some(ctx),
+                message: msg,
+            });
+        }
+    }
+}
+
+fn diagnose_low_cohesion(
+    cohesion_data: &[deps::ModuleCohesion],
+    diagnostics: &mut Vec<Diagnostic>,
+) {
+    for mc in cohesion_data {
+        if mc.function_count <= 1 {
+            continue;
+        }
+        let (sev, thresh) = if mc.combined < COHESION.alert {
+            (Some(Severity::Alert), COHESION.alert)
+        } else if mc.combined < COHESION.warn {
+            (Some(Severity::Warn), COHESION.warn)
+        } else {
+            (None, 0.0)
+        };
+
+        if let Some(severity) = sev {
+            let ctx = serde_json::json!({
+                "call_cohesion": mc.call_cohesion,
+                "type_cohesion": mc.type_cohesion,
+                "function_count": mc.function_count,
+            });
+            let msg = format!(
+                "{} has cohesion {:.2} (call {:.2}, type {:.2}, {} functions)",
+                mc.module, mc.combined, mc.call_cohesion, mc.type_cohesion, mc.function_count
+            );
+            diagnostics.push(Diagnostic {
+                severity,
+                category: Category::LowCohesion,
+                location: mod_location(&mc.module),
+                metric: mc.combined,
+                threshold: thresh,
+                context: Some(ctx),
+                message: msg,
+            });
+        }
+    }
+}
+
+// ── Helpers ──────────────────────────────────────────────────────
+
+fn check_threshold(value: f64, thresh: &Threshold) -> Option<(Severity, f64)> {
+    if value > thresh.alert {
+        Some((Severity::Alert, thresh.alert))
+    } else if value > thresh.warn {
+        Some((Severity::Warn, thresh.warn))
+    } else {
+        None
+    }
+}
+
+fn make_location(file: Option<&str>, function: Option<&str>, module: Option<&str>) -> Location {
+    Location {
+        file: file.map(str::to_string),
+        function: function.map(str::to_string),
+        module: module.map(str::to_string),
+        line_start: None,
+        line_end: None,
+    }
+}
+
+fn fn_location(name: &str, file: &str) -> Location {
+    make_location(Some(file), Some(name), None)
+}
+
+fn mod_location(module: &str) -> Location {
+    make_location(None, None, Some(module))
+}

src/diagnostics/scoring.rs

@@ -0,0 +1,220 @@
+use std::path::{Path, PathBuf};
+
+use crate::circuits;
+use crate::complexity;
+use crate::deps;
+use crate::flow;
+use crate::loc;
+use crate::redundancy;
+
+use super::{HealthScores, COGNITIVE, CYCLOMATIC, FILE_LOC, REDUNDANCY};
+
+pub(super) fn compute_health_scores(
+    file_stats: &[loc::FileLocStats],
+    func_complexities: &[complexity::FunctionComplexity],
+    dep_analysis: &deps::DepAnalysis,
+    redundant_pairs: &[redundancy::RedundantPair],
+    call_graph: &flow::CallGraph,
+    reachable: &std::collections::HashSet<String>,
+    rs_files: &[PathBuf],
+    project_path: &Path,
+) -> HealthScores {
+    let modularity = compute_modularity_score(dep_analysis, rs_files, project_path);
+    let complexity = compute_complexity_score(func_complexities);
+    let maintainability = compute_maintainability_score(
+        file_stats,
+        func_complexities,
+        redundant_pairs,
+        call_graph,
+        reachable,
+        modularity,
+        complexity,
+    );
+
+    HealthScores {
+        modularity,
+        complexity,
+        maintainability,
+    }
+}
+
+fn compute_modularity_score(
+    dep_analysis: &deps::DepAnalysis,
+    rs_files: &[PathBuf],
+    project_path: &Path,
+) -> f64 {
+    if dep_analysis.modules.is_empty() {
+        return 1.0;
+    }
+
+    let bidi_count = dep_analysis
+        .coupling_pairs
+        .iter()
+        .filter(|(_, _, s)| *s >= 2)
+        .count();
+    let total_pairs = dep_analysis.coupling_pairs.len().max(1);
+    let coupling_ratio = bidi_count as f64 / total_pairs as f64;
+    let coupling_score = 1.0 - coupling_ratio;
+
+    let modularity_q = circuits::circuit_summary(rs_files, project_path)
+        .map(|cs| cs.modularity)
+        .unwrap_or(0.0);
+    let q_score = ((modularity_q + 0.5) / 1.5).clamp(0.0, 1.0);
+
+    (0.5 * coupling_score + 0.5 * q_score).clamp(0.0, 1.0)
+}
+
+fn compute_complexity_score(func_complexities: &[complexity::FunctionComplexity]) -> f64 {
+    if func_complexities.is_empty() {
+        return 1.0;
+    }
+
+    let clean_cycl = func_complexities
+        .iter()
+        .filter(|fc| (fc.cyclomatic as f64) <= CYCLOMATIC.warn)
+        .count();
+    let cycl_ratio = clean_cycl as f64 / func_complexities.len() as f64;
+
+    let clean_cogn = func_complexities
+        .iter()
+        .filter(|fc| (fc.cognitive as f64) <= COGNITIVE.warn)
+        .count();
+    let cogn_ratio = clean_cogn as f64 / func_complexities.len() as f64;
+
+    let mut scores: Vec<f64> = func_complexities
+        .iter()
+        .map(|fc| fc.composite_score)
+        .collect();
+    scores.sort_by(|a, b| a.partial_cmp(b).unwrap_or(std::cmp::Ordering::Equal));
+    let median = if scores.len() % 2 == 0 {
+        (scores[scores.len() / 2 - 1] + scores[scores.len() / 2]) / 2.0
+    } else {
+        scores[scores.len() / 2]
+    };
+    let median_score = (1.0 - (median / 30.0)).clamp(0.0, 1.0);
+
+    (0.4 * cycl_ratio + 0.3 * cogn_ratio + 0.3 * median_score).clamp(0.0, 1.0)
+}
+
+fn compute_maintainability_score(
+    file_stats: &[loc::FileLocStats],
+    func_complexities: &[complexity::FunctionComplexity],
+    redundant_pairs: &[redundancy::RedundantPair],
+    call_graph: &flow::CallGraph,
+    reachable: &std::collections::HashSet<String>,
+    modularity: f64,
+    complexity: f64,
+) -> f64 {
+    let clean_files = file_stats
+        .iter()
+        .filter(|f| (f.code_lines as f64) <= FILE_LOC.warn)
+        .count();
+    let file_ratio = if file_stats.is_empty() {
+        1.0
+    } else {
+        clean_files as f64 / file_stats.len() as f64
+    };
+
+    let high_redundancy = redundant_pairs
+        .iter()
+        .filter(|p| p.similarity > REDUNDANCY.alert)
+        .count();
+    let total_funcs = func_complexities.len().max(1);
+    let redundancy_ratio =
+        (1.0 - (high_redundancy as f64 * 2.0 / total_funcs as f64)).clamp(0.0, 1.0);
+
+    let dead_ratio = if call_graph.functions.is_empty() {
+        1.0
+    } else {
+        let dead = call_graph
+            .functions
+            .iter()
+            .filter(|f| !reachable.contains(*f))
+            .count();
+        (1.0 - dead as f64 / call_graph.functions.len() as f64).clamp(0.0, 1.0)
+    };
+
+    (0.25 * modularity
+        + 0.25 * complexity
+        + 0.2 * file_ratio
+        + 0.15 * redundancy_ratio
+        + 0.15 * dead_ratio)
+        .clamp(0.0, 1.0)
+}
+
+// ── Simple Tarjan SCC (to avoid depending on graph module internals) ─
+
+pub(super) fn tarjan_scc_simple(
+    nodes: &[String],
+    adj: &std::collections::HashMap<String, Vec<String>>,
+) -> Vec<Vec<String>> {
+    struct State {
+        index_counter: usize,
+        stack: Vec<String>,
+        on_stack: std::collections::HashSet<String>,
+        index: std::collections::HashMap<String, usize>,
+        lowlink: std::collections::HashMap<String, usize>,
+        sccs: Vec<Vec<String>>,
+    }
+
+    fn strongconnect(
+        v: &str,
+        adj: &std::collections::HashMap<String, Vec<String>>,
+        state: &mut State,
+    ) {
+        state.index.insert(v.to_string(), state.index_counter);
+        state.lowlink.insert(v.to_string(), state.index_counter);
+        state.index_counter += 1;
+        state.stack.push(v.to_string());
+        state.on_stack.insert(v.to_string());
+
+        if let Some(neighbors) = adj.get(v) {
+            for w in neighbors {
+                if !state.index.contains_key(w.as_str()) {
+                    strongconnect(w, adj, state);
+                    let wll = state.lowlink[w.as_str()];
+                    let vll = state.lowlink.get_mut(v).unwrap();
+                    if wll < *vll {
+                        *vll = wll;
+                    }
+                } else if state.on_stack.contains(w.as_str()) {
+                    let wi = state.index[w.as_str()];
+                    let vll = state.lowlink.get_mut(v).unwrap();
+                    if wi < *vll {
+                        *vll = wi;
+                    }
+                }
+            }
+        }
+
+        if state.lowlink[v] == state.index[v] {
+            let mut component = Vec::new();
+            loop {
+                let w = state.stack.pop().unwrap();
+                state.on_stack.remove(&w);
+                component.push(w.clone());
+                if w == v {
+                    break;
+                }
+            }
+            state.sccs.push(component);
+        }
+    }
+
+    let mut state = State {
+        index_counter: 0,
+        stack: Vec::new(),
+        on_stack: std::collections::HashSet::new(),
+        index: std::collections::HashMap::new(),
+        lowlink: std::collections::HashMap::new(),
+        sccs: Vec::new(),
+    };
+
+    for node in nodes {
+        if !state.index.contains_key(node.as_str()) {
+            strongconnect(node, adj, &mut state);
+        }
+    }
+
+    state.sccs
+}

src/dist.rs

@@ -0,0 +1,706 @@
+use colored::Colorize;
+use serde::Serialize;
+use std::path::Path;
+
+use crate::complexity::{self, FunctionComplexity};
+use crate::render;
+
+// ── Metric extraction ──────────────────────────────────────────────
+
+const METRIC_NAMES: &[&str] = &["loc", "cyclomatic", "cognitive", "nesting", "params"];
+
+struct MetricSet {
+    /// One vector of values per metric, in METRIC_NAMES order.
+    columns: Vec<Vec<f64>>,
+}
+
+fn extract_metrics(fcs: &[FunctionComplexity]) -> MetricSet {
+    let mut columns: Vec<Vec<f64>> = vec![Vec::new(); METRIC_NAMES.len()];
+    for fc in fcs {
+        columns[0].push(fc.line_count as f64);
+        columns[1].push(fc.cyclomatic as f64);
+        columns[2].push(fc.cognitive as f64);
+        columns[3].push(fc.nesting_depth as f64);
+        columns[4].push(fc.param_count as f64);
+    }
+    MetricSet { columns }
+}
+
+// ── Statistics helpers ─────────────────────────────────────────────
+
+fn mean(v: &[f64]) -> f64 {
+    if v.is_empty() {
+        return 0.0;
+    }
+    v.iter().sum::<f64>() / v.len() as f64
+}
+
+fn std_dev(v: &[f64]) -> f64 {
+    if v.len() < 2 {
+        return 0.0;
+    }
+    let m = mean(v);
+    let var = v.iter().map(|x| (x - m) * (x - m)).sum::<f64>() / v.len() as f64;
+    var.sqrt()
+}
+
+fn pearson(x: &[f64], y: &[f64]) -> f64 {
+    let n = x.len();
+    if n < 2 {
+        return 0.0;
+    }
+    let mx = mean(x);
+    let my = mean(y);
+    let mut num = 0.0;
+    let mut dx2 = 0.0;
+    let mut dy2 = 0.0;
+    for i in 0..n {
+        let dx = x[i] - mx;
+        let dy = y[i] - my;
+        num += dx * dy;
+        dx2 += dx * dx;
+        dy2 += dy * dy;
+    }
+    let denom = (dx2 * dy2).sqrt();
+    if denom < 1e-12 {
+        0.0
+    } else {
+        num / denom
+    }
+}
+
+fn skewness(v: &[f64]) -> f64 {
+    let n = v.len();
+    if n < 3 {
+        return 0.0;
+    }
+    let m = mean(v);
+    let s = std_dev(v);
+    if s < 1e-12 {
+        return 0.0;
+    }
+    let m3 = v.iter().map(|x| ((x - m) / s).powi(3)).sum::<f64>();
+    m3 / n as f64
+}
+
+fn kurtosis(v: &[f64]) -> f64 {
+    let n = v.len();
+    if n < 4 {
+        return 0.0;
+    }
+    let m = mean(v);
+    let s = std_dev(v);
+    if s < 1e-12 {
+        return 0.0;
+    }
+    let m4 = v.iter().map(|x| ((x - m) / s).powi(4)).sum::<f64>();
+    m4 / n as f64 - 3.0 // excess kurtosis
+}
+
+// ── Histogram ──────────────────────────────────────────────────────
+
+fn render_histogram(values: &[f64], label: &str, num_bins: usize, verbose: bool) {
+    if values.is_empty() {
+        return;
+    }
+
+    let min_v = values.iter().cloned().fold(f64::INFINITY, f64::min);
+    let max_v = values.iter().cloned().fold(f64::NEG_INFINITY, f64::max);
+
+    // Cap bins to the actual range for integer-valued data
+    let range = max_v - min_v;
+    let num_bins = if range.abs() < 1e-12 {
+        1
+    } else {
+        let int_range = range.ceil() as usize;
+        num_bins.min(int_range.max(1))
+    };
+    let bin_width = if num_bins == 1 {
+        1.0
+    } else {
+        range / num_bins as f64
+    };
+
+    let mut bins = vec![0usize; num_bins];
+    for &v in values {
+        let idx = if num_bins == 1 {
+            0
+        } else {
+            ((v - min_v) / bin_width).floor() as usize
+        };
+        let idx = idx.min(num_bins - 1);
+        bins[idx] += 1;
+    }
+
+    let max_count = *bins.iter().max().unwrap_or(&1).max(&1);
+
+    let term_w = render::terminal_width();
+    let label_w = 12; // "  [xxx, yyy)"
+    let count_w = format!("{}", max_count).len() + 1;
+    let bar_budget = term_w.saturating_sub(label_w + count_w + 4).max(10);
+
+    println!(
+        "\n  {} (n={})",
+        label.bright_cyan().bold(),
+        format!("{}", values.len()).bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Histogram: frequency distribution of values. Each row is a bin range.",
+            "Bar length proportional to count. Color: red = most frequent, green = least.",
+            "Stats below: skew > 0 = right-tailed (few very high values),",
+            "  excess kurtosis > 0 = heavy tails (more outliers than a normal distribution).",
+        ]);
+        render::guide_ref("complexity");
+    }
+
+    for i in 0..num_bins {
+        let lo = min_v + i as f64 * bin_width;
+        let hi = lo + bin_width;
+        let range_label = if num_bins == 1 {
+            format!("[{:.0}]", lo)
+        } else if i == num_bins - 1 {
+            format!("[{:.0},{:.0}]", lo, hi)
+        } else {
+            format!("[{:.0},{:.0})", lo, hi)
+        };
+
+        let bar_len = if max_count > 0 {
+            (bins[i] as f64 / max_count as f64 * bar_budget as f64).ceil() as usize
+        } else {
+            0
+        }
+        .max(if bins[i] > 0 { 1 } else { 0 });
+
+        let ratio = if max_count > 0 {
+            1.0 - (bins[i] as f64 / max_count as f64)
+        } else {
+            1.0
+        };
+        let bar = render::bar_color(&"█".repeat(bar_len), ratio);
+
+        println!(
+            "  {:>10} │ {}{} {}",
+            range_label.dimmed(),
+            bar,
+            " ".repeat(bar_budget.saturating_sub(bar_len)),
+            format!("{}", bins[i]).bold(),
+        );
+    }
+
+    // Distribution shape stats
+    let m = mean(values);
+    let sd = std_dev(values);
+    let sk = skewness(values);
+    let ku = kurtosis(values);
+    println!(
+        "  {} mean={:.1} σ={:.1} skew={:.2} kurt={:.2}",
+        "↳".dimmed(),
+        m,
+        sd,
+        sk,
+        ku
+    );
+}
+
+// ── Scatter plot ───────────────────────────────────────────────────
+
+fn render_scatter(x: &[f64], y: &[f64], x_label: &str, y_label: &str, verbose: bool) {
+    if x.is_empty() {
+        return;
+    }
+
+    let r = pearson(x, y);
+
+    println!(
+        "\n{}",
+        format!("── {} vs {} (r={:.3}) ", x_label, y_label, r)
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Scatter plot: each ● represents one or more functions at that (x, y) position.",
+            "  Green ● = 1 function, Yellow ● = 2-3, Red ● = 4+ (overlapping).",
+            "  · = empty cell. X-axis = LoC, Y-axis = composite complexity.",
+            "Pearson r measures linear correlation: r > 0.7 = strong positive,",
+            "  r ≈ 0 = no linear relationship, r < -0.7 = strong negative.",
+        ]);
+    }
+
+    let plot_w: usize = render::terminal_width().min(72).saturating_sub(8);
+    let plot_h: usize = 20;
+
+    let x_min = x.iter().cloned().fold(f64::INFINITY, f64::min);
+    let x_max = x.iter().cloned().fold(f64::NEG_INFINITY, f64::max);
+    let y_min = y.iter().cloned().fold(f64::INFINITY, f64::min);
+    let y_max = y.iter().cloned().fold(f64::NEG_INFINITY, f64::max);
+
+    let x_range = if (x_max - x_min).abs() < 1e-12 {
+        1.0
+    } else {
+        x_max - x_min
+    };
+    let y_range = if (y_max - y_min).abs() < 1e-12 {
+        1.0
+    } else {
+        y_max - y_min
+    };
+
+    // Build grid with counts
+    let mut grid = vec![vec![0u32; plot_w]; plot_h];
+    for i in 0..x.len() {
+        let col = ((x[i] - x_min) / x_range * (plot_w - 1) as f64).round() as usize;
+        let row = ((y[i] - y_min) / y_range * (plot_h - 1) as f64).round() as usize;
+        let col = col.min(plot_w - 1);
+        let row = row.min(plot_h - 1);
+        grid[row][col] += 1;
+    }
+
+    // Render top to bottom (high y first)
+    let y_label_w = 6;
+    for row in (0..plot_h).rev() {
+        let y_val = y_min + (row as f64 / (plot_h - 1).max(1) as f64) * y_range;
+        let label = if row == plot_h - 1 || row == 0 || row == plot_h / 2 {
+            format!("{:>5.0}", y_val)
+        } else {
+            "     ".to_string()
+        };
+
+        let mut line = String::new();
+        for col in 0..plot_w {
+            let count = grid[row][col];
+            if count == 0 {
+                line.push('·');
+            } else if count == 1 {
+                line.push_str(&"●".green().to_string());
+            } else if count < 4 {
+                line.push_str(&"●".yellow().to_string());
+            } else {
+                line.push_str(&"●".red().bold().to_string());
+            }
+        }
+
+        let border = if row == 0 { "└" } else { "│" };
+        println!("{} {}{}", label.dimmed(), border, line);
+    }
+
+    // X axis
+    let x_min_s = format!("{:.0}", x_min);
+    let x_max_s = format!("{:.0}", x_max);
+    let mid_x = (x_min + x_max) / 2.0;
+    let x_mid_s = format!("{:.0}", mid_x);
+    let axis_padding = plot_w.saturating_sub(x_min_s.len() + x_max_s.len() + x_mid_s.len()) / 2;
+    println!(
+        "{} {}{}{}{}{}",
+        " ".repeat(y_label_w),
+        x_min_s.dimmed(),
+        " ".repeat(axis_padding),
+        x_mid_s.dimmed(),
+        " ".repeat(axis_padding),
+        x_max_s.dimmed(),
+    );
+    println!(
+        "{}  {} →  {}   {} ↑",
+        " ".repeat(y_label_w),
+        x_label.dimmed(),
+        y_label.dimmed(),
+        format!("r={:.3}", r).bold(),
+    );
+}
+
+// ── Outlier detection ──────────────────────────────────────────────
+
+fn render_outliers(fcs: &[FunctionComplexity], metrics: &MetricSet, verbose: bool) {
+    println!(
+        "\n{}",
+        "── Outliers (z-score > 2.0) ───────────────────────────"
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Outlier detection: functions with a z-score > 2.0 in any metric.",
+            "z-score = (value - mean) / standard deviation. z > 2.0 means the value is",
+            "more than 2 standard deviations above the mean — statistically unusual.",
+            "These are candidates for refactoring or closer inspection.",
+            "Grouped by metric, showing up to 5 outliers per metric.",
+        ]);
+    }
+
+    let mut any_outlier = false;
+
+    for (mi, metric_name) in METRIC_NAMES.iter().enumerate() {
+        let vals = &metrics.columns[mi];
+        let m = mean(vals);
+        let s = std_dev(vals);
+        if s < 1e-12 {
+            continue;
+        }
+
+        let mut outliers: Vec<(usize, f64)> = Vec::new();
+        for (i, &v) in vals.iter().enumerate() {
+            let z = (v - m) / s;
+            if z > 2.0 {
+                outliers.push((i, z));
+            }
+        }
+        outliers.sort_by(|a, b| b.1.partial_cmp(&a.1).unwrap_or(std::cmp::Ordering::Equal));
+
+        if !outliers.is_empty() {
+            any_outlier = true;
+            println!(
+                "\n  {} ({} outlier{})",
+                metric_name.yellow().bold(),
+                outliers.len(),
+                if outliers.len() == 1 { "" } else { "s" }
+            );
+
+            for (i, z) in outliers.iter().take(5) {
+                let name = if fcs[*i].name.len() > 45 {
+                    format!("{}...", &fcs[*i].name[..42])
+                } else {
+                    fcs[*i].name.clone()
+                };
+                println!(
+                    "    {} {} (z={:.2}, val={:.0})",
+                    "▸".red(),
+                    name.dimmed(),
+                    z,
+                    vals[*i],
+                );
+            }
+        }
+    }
+
+    if !any_outlier {
+        println!("  {}", "No outliers detected.".dimmed());
+    }
+}
+
+// ── Correlation matrix ─────────────────────────────────────────────
+
+fn render_correlation_matrix(metrics: &MetricSet, verbose: bool) {
+    let n = METRIC_NAMES.len();
+
+    println!(
+        "\n{}",
+        "── Correlation Matrix ─────────────────────────────────"
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Pairwise Pearson correlation coefficients (r) between all metrics.",
+            "r ranges from -1.0 (perfect negative) to +1.0 (perfect positive).",
+            "Color: red/bold = strong positive (r > 0.7), blue/bold = strong negative (r < -0.7),",
+            "  yellow = moderate positive (r > 0.4), cyan = moderate negative (r < -0.4),",
+            "  dim = weak correlation (|r| ≤ 0.4).",
+            "Diagonal is always 1.000 (a metric perfectly correlates with itself).",
+            "High correlation between two metrics suggests redundancy or a shared underlying factor.",
+        ]);
+    }
+
+    // Header row
+    print!("  {:>12}", "");
+    for name in METRIC_NAMES {
+        print!(" {:>10}", name.bold());
+    }
+    println!();
+
+    for i in 0..n {
+        print!("  {:>12}", METRIC_NAMES[i].bold());
+        for j in 0..n {
+            let r = pearson(&metrics.columns[i], &metrics.columns[j]);
+            let cell = format!("{:>7.3}", r);
+            let colored = color_correlation(&cell, r);
+            print!("   {}", colored);
+        }
+        println!();
+    }
+}
+
+fn color_correlation(text: &str, r: f64) -> String {
+    let abs_r = r.abs();
+    if abs_r > 0.7 {
+        if r > 0.0 {
+            text.red().bold().to_string()
+        } else {
+            text.blue().bold().to_string()
+        }
+    } else if abs_r > 0.4 {
+        if r > 0.0 {
+            text.yellow().to_string()
+        } else {
+            text.cyan().to_string()
+        }
+    } else {
+        text.dimmed().to_string()
+    }
+}
+
+// ── Public entry point ─────────────────────────────────────────────
+
+pub fn render_dist(
+    rs_files: &[std::path::PathBuf],
+    project_path: &Path,
+    metric_filter: Option<&str>,
+    num_bins: usize,
+    verbose: bool,
+) {
+    let symbols = crate::ast_parser::parse_project(rs_files);
+    let fcs = complexity::compute_all(&symbols, project_path);
+
+    if fcs.is_empty() {
+        println!("{}", "No functions found to analyze.".yellow());
+        return;
+    }
+
+    let metrics = extract_metrics(&fcs);
+
+    println!(
+        "\n{}",
+        "── Distribution Analysis ──────────────────────────────"
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Statistical distribution analysis of complexity metrics across all functions.",
+            "Histograms show frequency distributions. Scatter plot shows LoC vs complexity.",
+            "Outliers are functions with z-score > 2.0 (more than 2σ above the mean).",
+            "Correlation matrix shows pairwise Pearson r between all metrics.",
+        ]);
+    }
+
+    println!(
+        "{} functions across {} files\n",
+        format!("{}", fcs.len()).bold(),
+        format!("{}", rs_files.len()).bold(),
+    );
+
+    // Histograms
+    let labels = &[
+        "Function LoC",
+        "Cyclomatic",
+        "Cognitive",
+        "Nesting Depth",
+        "Param Count",
+    ];
+
+    if let Some(filter) = metric_filter {
+        // Find the matching metric
+        let filter_lower = filter.to_lowercase();
+        if let Some(idx) = METRIC_NAMES.iter().position(|&n| n == filter_lower) {
+            render_histogram(&metrics.columns[idx], labels[idx], num_bins, verbose);
+        } else {
+            println!(
+                "{} Unknown metric '{}'. Available: {}",
+                "Error:".red().bold(),
+                filter,
+                METRIC_NAMES.join(", "),
+            );
+            return;
+        }
+    } else {
+        for (i, label) in labels.iter().enumerate() {
+            render_histogram(&metrics.columns[i], label, num_bins, verbose);
+        }
+    }
+
+    // Scatter plot: complexity (composite score) vs LoC
+    let composite_scores: Vec<f64> = fcs.iter().map(|f| f.composite_score).collect();
+    render_scatter(
+        &metrics.columns[0], // LoC
+        &composite_scores,
+        "Function LoC",
+        "Complexity",
+        verbose,
+    );
+
+    // Outlier detection
+    render_outliers(&fcs, &metrics, verbose);
+
+    // Correlation matrix
+    render_correlation_matrix(&metrics, verbose);
+
+    println!();
+}
+
+#[derive(Serialize)]
+struct HistogramBinJson {
+    low: f64,
+    high: f64,
+    count: usize,
+}
+
+#[derive(Serialize)]
+struct HistogramJson {
+    metric: String,
+    bins: Vec<HistogramBinJson>,
+    mean: f64,
+    std_dev: f64,
+    skewness: f64,
+    kurtosis: f64,
+}
+
+#[derive(Serialize)]
+struct OutlierJson {
+    metric: String,
+    function: String,
+    z_score: f64,
+    value: f64,
+}
+
+#[derive(Serialize)]
+struct CorrelationEntryJson {
+    metric_a: String,
+    metric_b: String,
+    pearson_r: f64,
+}
+
+#[derive(Serialize)]
+struct DistJson {
+    cstat_version: String,
+    histograms: Vec<HistogramJson>,
+    outliers: Vec<OutlierJson>,
+    correlations: Vec<CorrelationEntryJson>,
+}
+
+fn compute_histogram_bins(values: &[f64], num_bins: usize) -> Vec<HistogramBinJson> {
+    if values.is_empty() {
+        return vec![];
+    }
+
+    let min_v = values.iter().cloned().fold(f64::INFINITY, f64::min);
+    let max_v = values.iter().cloned().fold(f64::NEG_INFINITY, f64::max);
+    let range = max_v - min_v;
+    let num_bins = if range.abs() < 1e-12 {
+        1
+    } else {
+        let int_range = range.ceil() as usize;
+        num_bins.min(int_range.max(1))
+    };
+    let bin_width = if num_bins == 1 {
+        1.0
+    } else {
+        range / num_bins as f64
+    };
+
+    let mut counts = vec![0usize; num_bins];
+    for &v in values {
+        let idx = if num_bins == 1 {
+            0
+        } else {
+            ((v - min_v) / bin_width).floor() as usize
+        };
+        let idx = idx.min(num_bins - 1);
+        counts[idx] += 1;
+    }
+
+    (0..num_bins)
+        .map(|i| {
+            let lo = min_v + i as f64 * bin_width;
+            let hi = lo + bin_width;
+            HistogramBinJson {
+                low: lo,
+                high: hi,
+                count: counts[i],
+            }
+        })
+        .collect()
+}
+
+/// Render distribution analysis as JSON.
+pub fn render_dist_json(
+    rs_files: &[std::path::PathBuf],
+    project_path: &std::path::Path,
+    metric_filter: Option<&str>,
+    num_bins: usize,
+) {
+    let symbols = crate::ast_parser::parse_project(rs_files);
+    let fcs = complexity::compute_all(&symbols, project_path);
+    let metrics = extract_metrics(&fcs);
+
+    let labels = &["loc", "cyclomatic", "cognitive", "nesting", "params"];
+
+    let indices: Vec<usize> = if let Some(filter) = metric_filter {
+        let filter_lower = filter.to_lowercase();
+        if let Some(idx) = METRIC_NAMES.iter().position(|&n| n == filter_lower) {
+            vec![idx]
+        } else {
+            vec![]
+        }
+    } else {
+        (0..METRIC_NAMES.len()).collect()
+    };
+
+    let histograms: Vec<HistogramJson> = indices
+        .iter()
+        .map(|&i| {
+            let vals = &metrics.columns[i];
+            let bins_json = compute_histogram_bins(vals, num_bins);
+            HistogramJson {
+                metric: labels[i].to_string(),
+                bins: bins_json,
+                mean: mean(vals),
+                std_dev: std_dev(vals),
+                skewness: skewness(vals),
+                kurtosis: kurtosis(vals),
+            }
+        })
+        .collect();
+
+    let mut outliers_json: Vec<OutlierJson> = Vec::new();
+    for (mi, metric_name) in METRIC_NAMES.iter().enumerate() {
+        let vals = &metrics.columns[mi];
+        let m = mean(vals);
+        let s = std_dev(vals);
+        if s < 1e-12 {
+            continue;
+        }
+        for (i, &v) in vals.iter().enumerate() {
+            let z = (v - m) / s;
+            if z > 2.0 {
+                outliers_json.push(OutlierJson {
+                    metric: metric_name.to_string(),
+                    function: fcs[i].name.clone(),
+                    z_score: z,
+                    value: v,
+                });
+            }
+        }
+    }
+    outliers_json.sort_by(|a, b| {
+        b.z_score
+            .partial_cmp(&a.z_score)
+            .unwrap_or(std::cmp::Ordering::Equal)
+    });
+
+    let n = METRIC_NAMES.len();
+    let mut correlations: Vec<CorrelationEntryJson> = Vec::new();
+    for i in 0..n {
+        for j in (i + 1)..n {
+            let r = pearson(&metrics.columns[i], &metrics.columns[j]);
+            correlations.push(CorrelationEntryJson {
+                metric_a: METRIC_NAMES[i].to_string(),
+                metric_b: METRIC_NAMES[j].to_string(),
+                pearson_r: r,
+            });
+        }
+    }
+
+    let output = DistJson {
+        cstat_version: env!("CARGO_PKG_VERSION").to_string(),
+        histograms,
+        outliers: outliers_json,
+        correlations,
+    };
+
+    println!("{}", serde_json::to_string(&output).unwrap());
+}

src/dump.rs

@@ -0,0 +1,248 @@
+use serde::Serialize;
+use std::collections::BTreeMap;
+use std::path::{Path, PathBuf};
+
+use crate::ast_parser;
+use crate::complexity;
+use crate::deps;
+use crate::diagnostics;
+use crate::loc;
+
+// ── Top-level dump output ────────────────────────────────────────
+
+#[derive(Serialize)]
+struct DumpOutput {
+    cstat_version: String,
+    project: ProjectInfo,
+    scores: diagnostics::HealthScores,
+    diagnostic_counts: DiagnosticCounts,
+    worst_items: Vec<diagnostics::Diagnostic>,
+    suggested_drilldowns: Vec<Drilldown>,
+}
+
+#[derive(Serialize)]
+struct ProjectInfo {
+    files: usize,
+    total_loc: usize,
+    functions: usize,
+    modules: usize,
+}
+
+// ── Diagnostic counts ───────────────────────────────────────────
+
+#[derive(Serialize)]
+struct DiagnosticCounts {
+    total: usize,
+    alerts: usize,
+    warns: usize,
+    by_category: BTreeMap<String, CategoryCounts>,
+}
+
+#[derive(Serialize)]
+struct CategoryCounts {
+    alerts: usize,
+    warns: usize,
+}
+
+// ── Drilldowns ──────────────────────────────────────────────────
+
+#[derive(Serialize)]
+struct Drilldown {
+    command: String,
+    reason: String,
+}
+
+// ── Public entry point ───────────────────────────────────────────
+
+pub fn render_dump(rs_files: &[PathBuf], project_path: &Path) {
+    let version = env!("CARGO_PKG_VERSION").to_string();
+
+    let (file_stats, agg_loc) = loc::analyze_files(rs_files);
+    let symbols = ast_parser::parse_project(rs_files);
+    let func_complexities = complexity::compute_all(&symbols, project_path);
+    let dep_analysis = deps::analyze_deps(rs_files, project_path);
+
+    let report = diagnostics::run_diagnostics(rs_files, project_path);
+
+    let project = ProjectInfo {
+        files: file_stats.len(),
+        total_loc: agg_loc.as_ref().map(|a| a.total_loc).unwrap_or(0),
+        functions: func_complexities.len(),
+        modules: dep_analysis.modules.len(),
+    };
+
+    let diagnostic_counts = build_diagnostic_counts(&report.diagnostics);
+    let worst_items = build_worst_items(&report.diagnostics);
+    let suggested_drilldowns = build_drilldowns(&report.diagnostics);
+
+    let output = DumpOutput {
+        cstat_version: version,
+        project,
+        scores: report.scores,
+        diagnostic_counts,
+        worst_items,
+        suggested_drilldowns,
+    };
+
+    println!("{}", serde_json::to_string(&output).unwrap());
+}
+
+// ── Diagnostic count builder ────────────────────────────────────
+
+fn build_diagnostic_counts(diagnostics: &[diagnostics::Diagnostic]) -> DiagnosticCounts {
+    let mut total_alerts = 0usize;
+    let mut total_warns = 0usize;
+    let mut by_category: BTreeMap<String, CategoryCounts> = BTreeMap::new();
+
+    // Initialize all categories so they always appear
+    let all_categories = [
+        "bloated_function",
+        "redundant_code",
+        "high_cognitive",
+        "high_complexity",
+        "deep_nesting",
+        "dead_code",
+        "bloated_file",
+        "low_cohesion",
+        "too_many_params",
+        "god_module",
+        "high_coupling",
+        "cyclic_deps",
+    ];
+    for cat in &all_categories {
+        by_category.insert(
+            cat.to_string(),
+            CategoryCounts {
+                alerts: 0,
+                warns: 0,
+            },
+        );
+    }
+
+    for d in diagnostics {
+        let cat_name = category_name(&d.category);
+        let entry = by_category.entry(cat_name).or_insert(CategoryCounts {
+            alerts: 0,
+            warns: 0,
+        });
+        match d.severity {
+            diagnostics::Severity::Alert => {
+                total_alerts += 1;
+                entry.alerts += 1;
+            }
+            diagnostics::Severity::Warn => {
+                total_warns += 1;
+                entry.warns += 1;
+            }
+        }
+    }
+
+    DiagnosticCounts {
+        total: diagnostics.len(),
+        alerts: total_alerts,
+        warns: total_warns,
+        by_category,
+    }
+}
+
+// ── Worst items (top 5) ─────────────────────────────────────────
+
+fn build_worst_items(diagnostics: &[diagnostics::Diagnostic]) -> Vec<diagnostics::Diagnostic> {
+    // Sort: alerts first, then by metric magnitude descending.
+    let mut sorted: Vec<_> = diagnostics.to_vec();
+    sorted.sort_by(|a, b| {
+        let sev_order = |s: &diagnostics::Severity| match s {
+            diagnostics::Severity::Alert => 0,
+            diagnostics::Severity::Warn => 1,
+        };
+        sev_order(&a.severity)
+            .cmp(&sev_order(&b.severity))
+            .then_with(|| {
+                b.metric
+                    .partial_cmp(&a.metric)
+                    .unwrap_or(std::cmp::Ordering::Equal)
+            })
+    });
+    sorted.into_iter().take(5).collect()
+}
+
+// ── Drilldown suggestions ───────────────────────────────────────
+
+fn build_drilldowns(diagnostics: &[diagnostics::Diagnostic]) -> Vec<Drilldown> {
+    // Count alerts per category
+    let mut alert_counts: BTreeMap<String, usize> = BTreeMap::new();
+    for d in diagnostics {
+        if d.severity == diagnostics::Severity::Alert {
+            *alert_counts.entry(category_name(&d.category)).or_insert(0) += 1;
+        }
+    }
+
+    // Map categories to subcommands
+    let category_to_command: &[(&[&str], &str)] = &[
+        (
+            &["high_complexity", "high_cognitive", "deep_nesting"],
+            "cstat branching --json",
+        ),
+        (&["too_many_params"], "cstat signature --json"),
+        (&["bloated_function"], "cstat span --json"),
+        (&["redundant_code"], "cstat redundancy --json"),
+        (&["bloated_file"], "cstat loc --json"),
+        (
+            &["low_cohesion", "high_coupling", "god_module"],
+            "cstat deps --json",
+        ),
+        (&["dead_code"], "cstat test-reachability --json"),
+        (&["cyclic_deps"], "cstat graph --json"),
+    ];
+
+    let mut drilldowns: Vec<(usize, String, Vec<String>)> = Vec::new();
+
+    for (categories, command) in category_to_command {
+        let mut total_alerts = 0usize;
+        let mut reasons: Vec<String> = Vec::new();
+
+        for cat in *categories {
+            if let Some(&count) = alert_counts.get(*cat) {
+                total_alerts += count;
+                let display = cat.replace('_', " ");
+                reasons.push(format!("{} alert-level {}", count, display));
+            }
+        }
+
+        if total_alerts > 0 {
+            drilldowns.push((total_alerts, command.to_string(), reasons));
+        }
+    }
+
+    // Sort by total alert count descending
+    drilldowns.sort_by(|a, b| b.0.cmp(&a.0));
+
+    drilldowns
+        .into_iter()
+        .map(|(_, command, reasons)| Drilldown {
+            command,
+            reason: reasons.join(", "),
+        })
+        .collect()
+}
+
+// ── Helpers ─────────────────────────────────────────────────────
+
+fn category_name(cat: &diagnostics::Category) -> String {
+    // Match the serde snake_case serialization
+    match cat {
+        diagnostics::Category::BloatedFile => "bloated_file",
+        diagnostics::Category::BloatedFunction => "bloated_function",
+        diagnostics::Category::HighComplexity => "high_complexity",
+        diagnostics::Category::HighCognitive => "high_cognitive",
+        diagnostics::Category::DeepNesting => "deep_nesting",
+        diagnostics::Category::HighCoupling => "high_coupling",
+        diagnostics::Category::GodModule => "god_module",
+        diagnostics::Category::DeadCode => "dead_code",
+        diagnostics::Category::LowCohesion => "low_cohesion",
+        diagnostics::Category::RedundantCode => "redundant_code",
+        diagnostics::Category::TooManyParams => "too_many_params",
+        diagnostics::Category::CyclicDeps => "cyclic_deps",
+    }
+    .to_string()
+}

src/file_summary.rs

@@ -0,0 +1,507 @@
+use colored::Colorize;
+use serde::Serialize;
+use std::collections::HashSet;
+use std::path::{Path, PathBuf};
+
+use crate::{
+    ast_parser, call_trace, datapaths, dead_code, deps, file_metrics, flow, loc, render, symbols,
+};
+
+#[derive(Debug, Clone, Serialize)]
+pub struct FileSummaryReport {
+    pub cstat_version: String,
+    pub file: String,
+    pub project: String,
+    pub line_counts: loc::FileProjectedLineReachabilityReport,
+    pub static_reachability: datapaths::FileStaticReachabilityReport,
+    pub symbols: symbols::FileSymbolReport,
+    pub dependencies: deps::FileDependencyReport,
+    pub dead_code: dead_code::FileDeadCodeReport,
+    pub call_trace: call_trace::FileCallTraceReport,
+}
+
+pub fn render_file_summary(rs_files: &[PathBuf], project_path: &Path, file: &Path, verbose: bool) {
+    let report = build_file_summary(rs_files, project_path, file);
+    render_file_summary_report(&report, verbose);
+}
+
+pub fn render_file_summary_json(rs_files: &[PathBuf], project_path: &Path, file: &Path) {
+    let report = build_file_summary(rs_files, project_path, file);
+    println!("{}", serde_json::to_string(&report).unwrap());
+}
+
+pub fn build_file_summary(
+    rs_files: &[PathBuf],
+    project_path: &Path,
+    file: &Path,
+) -> FileSummaryReport {
+    let file_display_path = call_trace::relative_path_string(project_path, file);
+    let project = project_name(project_path);
+
+    let symbols_raw = ast_parser::parse_project(rs_files);
+    let graph = flow::build_call_graph(rs_files, project_path);
+    let file_functions =
+        file_metrics::selected_file_functions(&symbols_raw, &graph, project_path, file);
+    let static_reachability =
+        datapaths::analyze_file_static_reachability(&graph, &file_functions, &file_display_path);
+    let reachable_functions: HashSet<String> = static_reachability
+        .reachable_functions
+        .iter()
+        .cloned()
+        .collect();
+    let line_counts = loc::analyze_file_projected_line_reachability(
+        file,
+        &file_functions,
+        &reachable_functions,
+        &file_display_path,
+    )
+    .unwrap_or_else(|| empty_line_report(file, &file_display_path));
+    let symbols = symbols::analyze_symbols_file(&symbols_raw, project_path, file);
+    let dependencies = deps::analyze_file_deps(rs_files, project_path, file);
+    let dead_code = dead_code::analyze_file_dead_code(&graph, &file_functions, &file_display_path);
+    let call_trace =
+        call_trace::analyze_file_call_traces(&graph, &file_functions, &file_display_path);
+
+    FileSummaryReport {
+        cstat_version: env!("CARGO_PKG_VERSION").to_string(),
+        file: file_display_path,
+        project,
+        line_counts,
+        static_reachability,
+        symbols,
+        dependencies,
+        dead_code,
+        call_trace,
+    }
+}
+
+fn project_name(project_path: &Path) -> String {
+    let fallback = || {
+        project_path
+            .file_name()
+            .map(|name| name.to_string_lossy().to_string())
+            .unwrap_or_else(|| "unknown".to_string())
+    };
+
+    let Ok(manifest) = std::fs::read_to_string(project_path.join("Cargo.toml")) else {
+        return fallback();
+    };
+
+    let mut in_package = false;
+    for line in manifest.lines() {
+        let trimmed = line.trim();
+        if trimmed.starts_with('[') && trimmed.ends_with(']') {
+            in_package = trimmed == "[package]";
+            continue;
+        }
+        if in_package {
+            if let Some(value) = trimmed.strip_prefix("name") {
+                if let Some((_, raw_name)) = value.split_once('=') {
+                    let name = raw_name.trim().trim_matches('"');
+                    if !name.is_empty() {
+                        return name.to_string();
+                    }
+                }
+            }
+        }
+    }
+
+    fallback()
+}
+
+fn empty_line_report(
+    file: &Path,
+    file_display_path: &str,
+) -> loc::FileProjectedLineReachabilityReport {
+    let stats = loc::count_file_lines(file);
+    loc::FileProjectedLineReachabilityReport {
+        file: file_display_path.to_string(),
+        total_lines: stats.as_ref().map_or(0, |stats| stats.total_lines),
+        code_lines: 0,
+        projected_reachable_lines: 0,
+        projected_unreachable_lines: 0,
+        reachable_spans: Vec::new(),
+        unreachable_spans: Vec::new(),
+    }
+}
+
+fn render_file_summary_report(report: &FileSummaryReport, verbose: bool) {
+    println!(
+        "\n{} {}",
+        "cstat file summary".bright_cyan().bold(),
+        format!("({})", report.file).dimmed(),
+    );
+    println!(
+        "{}",
+        "Single-file static metrics projected through the containing crate.".dimmed()
+    );
+
+    render_line_counts(&report.line_counts, &report.file, verbose);
+    render_static_reachability(&report.static_reachability, &report.file, verbose);
+    render_symbols(&report.symbols, &report.file, verbose);
+    render_dependencies(&report.dependencies, &report.file, verbose);
+    render_dead_code(&report.dead_code, &report.file, verbose);
+    render_call_trace(&report.call_trace, &report.file, verbose);
+}
+
+fn render_line_counts(
+    report: &loc::FileProjectedLineReachabilityReport,
+    file: &str,
+    verbose: bool,
+) {
+    render::section_header("Projected line reachability");
+    if verbose {
+        let full_section = format!("Full section: cstat loc --path {file} -v");
+        render::verbose_block(&[
+            "Production code lines exclude blank/comment-only lines and test/support/wrapper spans.",
+            "Projected reachable lines are static function spans reached from project tests/benches.",
+            full_section.as_str(),
+        ]);
+    }
+
+    let pct = percentage(report.projected_reachable_lines, report.code_lines);
+    println!(
+        "  {} {}  {} {}  {} {} / {} ({:.1}%)  {} {}",
+        "production code lines".cyan(),
+        report.code_lines.to_string().bold(),
+        "physical".cyan(),
+        report.total_lines.to_string().bold(),
+        "statically reachable".cyan(),
+        report.projected_reachable_lines.to_string().bold(),
+        report.code_lines,
+        pct,
+        "not statically reachable".cyan(),
+        report.projected_unreachable_lines.to_string().bold(),
+    );
+
+    if !report.reachable_spans.is_empty() {
+        println!();
+        println!("  {}", "reachable spans:".bold());
+        for span in report.reachable_spans.iter().take(6) {
+            println!(
+                "  {} lines {}-{}",
+                span.function, span.line_start, span.line_end
+            );
+        }
+        print_more(report.reachable_spans.len(), 6);
+    }
+
+    if !report.unreachable_spans.is_empty() {
+        println!();
+        println!("  {}", "unreachable spans:".bold().yellow());
+        for span in report.unreachable_spans.iter().take(6) {
+            println!(
+                "  {} lines {}-{}",
+                span.function, span.line_start, span.line_end
+            );
+        }
+        print_more(report.unreachable_spans.len(), 6);
+    }
+}
+
+fn render_static_reachability(
+    report: &datapaths::FileStaticReachabilityReport,
+    file: &str,
+    verbose: bool,
+) {
+    render::section_header("Static test/benchmark reachability");
+
+    if verbose {
+        let full_section = format!("Full section: cstat test-reachability --path {file} -v");
+        render::verbose_block(&[
+            "Roots are tests and benchmarks discovered anywhere in the project.",
+            "Reachability follows the full crate call graph, then projects production results onto this file.",
+            full_section.as_str(),
+        ]);
+    }
+
+    let pct = percentage(
+        report.reachable_function_count,
+        report.production_function_count,
+    );
+    println!(
+        "  {} {}  {} {} / {} ({:.1}%)  {} {} / {}",
+        "test/bench roots".cyan(),
+        report.test_benchmark_entry_count.to_string().bold(),
+        "functions reachable".cyan(),
+        report.reachable_function_count.to_string().bold(),
+        report.production_function_count,
+        pct,
+        "local edges reached".cyan(),
+        report.reachable_local_edge_count.to_string().bold(),
+        report.local_edge_count,
+    );
+
+    if !report.wrapper_entrypoints.is_empty() {
+        println!(
+            "  {} {}",
+            "wrapper entrypoints:".cyan(),
+            report.wrapper_entrypoints.join(", ")
+        );
+    }
+
+    if !report.entries.is_empty() {
+        println!();
+        println!(
+            "  {:<48} {:<7} {:>9} {:>7} {:>8}",
+            "entry root".bold(),
+            "kind".bold(),
+            "functions".bold(),
+            "steps".bold(),
+            "depth".bold(),
+        );
+        for entry in report.entries.iter().take(8) {
+            println!(
+                "  {:<48} {:<7} {:>9} {:>7} {:>8}",
+                truncate(&entry.entry, 48),
+                entry.kind,
+                entry.reachable_functions,
+                entry.unique_call_steps,
+                entry.max_call_depth,
+            );
+        }
+        print_more(report.entries.len(), 8);
+    }
+
+    println!();
+    println!("  {}", "not statically reachable:".bold().yellow());
+    if report.unreachable_functions.is_empty() {
+        println!("  {}", "<none>".dimmed());
+    } else {
+        for function in report.unreachable_functions.iter().take(8) {
+            println!("  {} {}", "•".yellow(), function);
+        }
+        print_more(report.unreachable_functions.len(), 8);
+    }
+}
+
+fn render_symbols(report: &symbols::FileSymbolReport, file: &str, verbose: bool) {
+    render::section_header("Symbols");
+    if verbose {
+        let full_section = format!("Full section: cstat symbols --path {file} -v");
+        render::verbose_block(&[
+            "Selected-file symbols use syn Rust AST item discovery.",
+            "Functions include free functions and impl methods once.",
+            full_section.as_str(),
+        ]);
+    }
+
+    println!(
+        "  {} {}  {} {}  {} {}  {} {}  {} {}  {} {}  {} {}  {} {}",
+        "total".cyan(),
+        report.total.to_string().bold(),
+        "fn".cyan(),
+        report.functions.to_string().bold(),
+        "struct".cyan(),
+        report.structs.to_string().bold(),
+        "enum".cyan(),
+        report.enums.to_string().bold(),
+        "trait".cyan(),
+        report.traits.to_string().bold(),
+        "trait_impl".cyan(),
+        report.trait_impls.to_string().bold(),
+        "const".cyan(),
+        report.consts.to_string().bold(),
+        "static".cyan(),
+        report.statics.to_string().bold(),
+    );
+
+    if report.parse_error {
+        println!(
+            "  {}",
+            "parse error: selected file could not be parsed"
+                .yellow()
+                .bold()
+        );
+    }
+
+    if !report.symbols.is_empty() {
+        println!();
+        println!("  {:<10} {}", "kind".bold(), "symbol".bold());
+        for row in report.symbols.iter().take(12) {
+            println!(
+                "  {:<10} {}",
+                file_symbol_kind_label(&row.kind),
+                truncate(&row.symbol, 60),
+            );
+        }
+        print_more(report.symbols.len(), 12);
+    }
+}
+
+fn render_dependencies(report: &deps::FileDependencyReport, file: &str, verbose: bool) {
+    render::section_header("Dependencies");
+    if verbose {
+        let full_section = format!("Full section: cstat deps --path {file} -v");
+        render::verbose_block(&[
+            "Imports are raw use/mod targets parsed from this file.",
+            "Internal imports resolve to known modules in the containing crate.",
+            full_section.as_str(),
+        ]);
+    }
+
+    println!(
+        "  {} {}  {} {}  {} {}  {} {}",
+        "module".cyan(),
+        report.module.bold(),
+        "imports".cyan(),
+        report.imports.to_string().bold(),
+        "internal".cyan(),
+        report.internal.len().to_string().bold(),
+        "external".cyan(),
+        report.external.len().to_string().bold(),
+    );
+
+    print_dependency_list("internal", &report.internal, 6, true);
+    print_dependency_list("external", &report.external, 6, false);
+}
+
+fn render_dead_code(report: &dead_code::FileDeadCodeReport, file: &str, verbose: bool) {
+    render::section_header("Dead code candidates");
+    if verbose {
+        let full_section = format!("Full section: cstat dead-code --path {file} -v");
+        render::verbose_block(&[
+            "Candidates are file functions not reachable from crate roots.",
+            "Fan-in distinguishes crate callers from callers inside this file.",
+            full_section.as_str(),
+        ]);
+    }
+
+    println!(
+        "  {} {} / {}  {} {} candidates",
+        "reached from crate roots".cyan(),
+        report.reached_from_crate_count.to_string().bold(),
+        report.file_function_count,
+        "cold".cyan(),
+        report.candidate_count.to_string().bold(),
+    );
+
+    let candidates: Vec<_> = report
+        .functions
+        .iter()
+        .filter(|function| function.candidate)
+        .collect();
+    println!();
+    println!(
+        "  {:<44} {:>11} {:>13}  {}",
+        "function".bold(),
+        "crate fan-in".bold(),
+        "in-file fan-in".bold(),
+        "reason".bold(),
+    );
+    if candidates.is_empty() {
+        println!("  {}", "<none>".dimmed());
+    } else {
+        for function in candidates.iter().take(8) {
+            println!(
+                "  {:<44} {:>11} {:>13}  {}",
+                truncate(&function.function, 44),
+                function.crate_fan_in,
+                function.in_file_fan_in,
+                function.reason,
+            );
+        }
+        print_more(candidates.len(), 8);
+    }
+}
+
+fn render_call_trace(report: &call_trace::FileCallTraceReport, file: &str, verbose: bool) {
+    render::section_header("Call trace size");
+    if verbose {
+        let full_section = format!("Full section: cstat call-trace --path {file} -v");
+        render::verbose_block(&[
+            "Rows rank non-test functions by the size of their static call tree.",
+            "Direct callees are truncated for the summary; full trees are in the section command.",
+            full_section.as_str(),
+        ]);
+    }
+
+    println!(
+        "  {:<44} {:>7} {:>5}  {}",
+        "function".bold(),
+        "reached".bold(),
+        "depth".bold(),
+        "direct callees".bold(),
+    );
+    let width = render::terminal_width();
+    let callee_width = width.saturating_sub(64).max(24);
+    for function in report.functions.iter().take(12) {
+        let callees = if function.direct_callees.is_empty() {
+            "-".to_string()
+        } else {
+            function.direct_callees.join(", ")
+        };
+        println!(
+            "  {:<44} {:>7} {:>5}  {}",
+            truncate(&function.function, 44),
+            function.functions_reached,
+            function.max_depth,
+            truncate(&callees, callee_width),
+        );
+    }
+    print_more(report.functions.len(), 12);
+}
+
+fn print_dependency_list(
+    label: &str,
+    dependencies: &[deps::FileDependency],
+    limit: usize,
+    show_resolved: bool,
+) {
+    println!();
+    println!("  {}", format!("{label} imports:").bold());
+    if dependencies.is_empty() {
+        println!("  {}", "<none>".dimmed());
+        return;
+    }
+
+    for dependency in dependencies.iter().take(limit) {
+        if show_resolved {
+            println!(
+                "  {} {} -> {}",
+                "•".cyan(),
+                dependency.raw,
+                dependency.resolved_module.as_deref().unwrap_or("-"),
+            );
+        } else {
+            println!("  {} {}", "•".cyan(), dependency.raw);
+        }
+    }
+    print_more(dependencies.len(), limit);
+}
+
+fn file_symbol_kind_label(kind: &symbols::FileSymbolKind) -> &'static str {
+    match kind {
+        symbols::FileSymbolKind::Fn => "fn",
+        symbols::FileSymbolKind::Struct => "struct",
+        symbols::FileSymbolKind::Enum => "enum",
+        symbols::FileSymbolKind::Trait => "trait",
+        symbols::FileSymbolKind::TraitImpl => "trait_impl",
+        symbols::FileSymbolKind::Const => "const",
+        symbols::FileSymbolKind::Static => "static",
+    }
+}
+
+fn percentage(numerator: usize, denominator: usize) -> f64 {
+    if denominator == 0 {
+        0.0
+    } else {
+        numerator as f64 / denominator as f64 * 100.0
+    }
+}
+
+fn print_more(total: usize, shown: usize) {
+    if total > shown {
+        println!("  … +{} more", total - shown);
+    }
+}
+
+fn truncate(value: &str, max: usize) -> String {
+    if value.chars().count() <= max {
+        value.to_string()
+    } else {
+        let mut out: String = value.chars().take(max.saturating_sub(1)).collect();
+        out.push('…');
+        out
+    }
+}

src/flow.rs

@@ -1,3 +1,4 @@
+use colored::Colorize;
 use serde::Serialize;
 use std::collections::{HashMap, HashSet};
 use std::path::{Path, PathBuf};
@@ -58,6 +59,8 @@ pub struct CallGraph {
     pub entry_points: Vec<String>,
     /// Entry point classification keyed by function name.
     pub entry_point_kinds: HashMap<String, EntryPointKind>,
+    /// Edges that form cycles.
+    pub cycle_edges: HashSet<(String, String)>,
 }
 
 #[derive(Debug, Clone)]
@@ -1446,6 +1449,49 @@ fn concrete_generic_method_edges(
     out
 }
 
+/// Detect cycles in the call graph using DFS. Returns the set of back-edges.
+fn detect_cycles(adjacency: &HashMap<String, Vec<String>>) -> HashSet<(String, String)> {
+    let mut cycle_edges = HashSet::new();
+    let mut visited = HashSet::new();
+    let mut on_stack = HashSet::new();
+
+    for node in adjacency.keys() {
+        if !visited.contains(node) {
+            dfs_cycle(
+                node,
+                adjacency,
+                &mut visited,
+                &mut on_stack,
+                &mut cycle_edges,
+            );
+        }
+    }
+    cycle_edges
+}
+
+fn dfs_cycle(
+    node: &str,
+    adjacency: &HashMap<String, Vec<String>>,
+    visited: &mut HashSet<String>,
+    on_stack: &mut HashSet<String>,
+    cycle_edges: &mut HashSet<(String, String)>,
+) {
+    visited.insert(node.to_string());
+    on_stack.insert(node.to_string());
+
+    if let Some(callees) = adjacency.get(node) {
+        for callee in callees {
+            if on_stack.contains(callee.as_str()) {
+                cycle_edges.insert((node.to_string(), callee.clone()));
+            } else if !visited.contains(callee.as_str()) {
+                dfs_cycle(callee, adjacency, visited, on_stack, cycle_edges);
+            }
+        }
+    }
+
+    on_stack.remove(node);
+}
+
 /// Build the call graph from all project files.
 pub fn build_call_graph(rs_files: &[PathBuf], project_path: &Path) -> CallGraph {
     let mut records = Vec::new();
@@ -1589,12 +1635,15 @@ pub fn build_call_graph(rs_files: &[PathBuf], project_path: &Path) -> CallGraph
         callees.retain(|c| seen.insert(c.clone()));
     }
 
+    let cycle_edges = detect_cycles(&adjacency);
+
     CallGraph {
         functions,
         function_nodes,
         adjacency,
         entry_points,
         entry_point_kinds,
+        cycle_edges,
     }
 }
 
@@ -1627,6 +1676,352 @@ pub fn entry_points_by_kind(call_graph: &CallGraph, kind: EntryPointKind) -> Vec
         .collect()
 }
 
+/// Render the call graph as a tree rooted at entry points.
+fn render_call_tree(graph: &CallGraph, verbose: bool) {
+    println!(
+        "\n{}",
+        "── Call Flow ─────────────────────────────────────────"
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Static call graph rendered as a tree rooted at entry points.",
+            "Entry points are main() and #[test] functions.",
+            "Each indented line is a callee of the function above it.",
+            "├── / └── = tree branch connectors. ─┬ = node has children below.",
+            "⟲ (red) = cycle detected — this call creates a recursive loop.",
+            "… (dimmed) = already visited in this tree — prevents infinite expansion.",
+            "⋯ (depth limit) = tree truncated at maximum display depth (12 levels).",
+            "Yellow-highlighted names = functions that themselves have callees.",
+        ]);
+        render::guide_ref("flow");
+    }
+
+    if graph.entry_points.is_empty() {
+        println!("  {}", "No entry points found.".dimmed());
+        return;
+    }
+
+    // Render from each entry point
+    for entry in &graph.entry_points {
+        println!();
+        println!("  {}", entry.bold().bright_white());
+        let mut visited = HashSet::new();
+        visited.insert(entry.clone());
+        render_subtree(graph, entry, "  ", &mut visited, 0);
+    }
+}
+
+/// Recursively render a subtree of the call graph.
+fn render_subtree(
+    graph: &CallGraph,
+    node: &str,
+    prefix: &str,
+    visited: &mut HashSet<String>,
+    depth: usize,
+) {
+    const MAX_DEPTH: usize = 12;
+
+    let callees = match graph.adjacency.get(node) {
+        Some(c) if !c.is_empty() => c,
+        _ => return,
+    };
+
+    let count = callees.len();
+    for (i, callee) in callees.iter().enumerate() {
+        let is_last = i == count - 1;
+        let connector = if is_last { "└── " } else { "├── " };
+        let child_prefix = if is_last { "    " } else { "│   " };
+
+        let is_cycle = graph
+            .cycle_edges
+            .contains(&(node.to_string(), callee.clone()));
+        let is_revisit = visited.contains(callee);
+
+        if is_cycle {
+            println!(
+                "{}{}{}",
+                prefix,
+                connector,
+                format!("{} ⟲ cycle", callee).red().bold(),
+            );
+        } else if is_revisit {
+            println!(
+                "{}{}{}",
+                prefix,
+                connector,
+                format!("{} …", callee).dimmed(),
+            );
+        } else if depth >= MAX_DEPTH {
+            println!(
+                "{}{}{}",
+                prefix,
+                connector,
+                format!("{} ⋯ (depth limit)", callee).dimmed(),
+            );
+        } else {
+            let has_children = graph
+                .adjacency
+                .get(callee.as_str())
+                .map_or(false, |c| !c.is_empty());
+
+            if has_children {
+                println!(
+                    "{}{}{}",
+                    prefix,
+                    connector.replace("── ", "─┬ "),
+                    callee.bright_yellow(),
+                );
+            } else {
+                println!("{}{}{}", prefix, connector, callee);
+            }
+
+            visited.insert(callee.clone());
+            let new_prefix = format!("{}{}", prefix, child_prefix);
+            render_subtree(graph, callee, &new_prefix, visited, depth + 1);
+        }
+    }
+}
+
+/// Render call graph statistics.
+fn render_stats(graph: &CallGraph, verbose: bool) {
+    println!(
+        "\n{}",
+        "── Call Graph Stats ──────────────────────────────────"
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Summary statistics for the call graph.",
+            "Functions = total discovered. Call edges = total caller→callee links.",
+            "Entry points = main() and #[test] functions. Cycles (red) = back-edges detected.",
+            "  Cycles = none (green) means the call graph is a DAG.",
+            "Fan-out (top callers): functions that call the most other functions.",
+            "  High fan-out = orchestrator or god function that coordinates many pieces.",
+            "  Bar (blue) length proportional to call count.",
+            "Hot paths (longest call chains): deepest call chain from each entry point.",
+            "  Depth = number of function hops from entry to deepest leaf.",
+            "  Color: red = depth > 6, yellow = depth > 3, white = shallow.",
+        ]);
+    }
+
+    let total_fns = graph.functions.len();
+    let total_edges: usize = graph.adjacency.values().map(|v| v.len()).sum();
+    let cycle_count = graph.cycle_edges.len();
+
+    println!();
+    println!("  Functions:    {}", format!("{}", total_fns).bold());
+    println!("  Call edges:   {}", format!("{}", total_edges).bold());
+    println!(
+        "  Entry points: {}",
+        format!("{}", graph.entry_points.len()).bold()
+    );
+
+    if cycle_count > 0 {
+        println!(
+            "  Cycles:       {}",
+            format!("{}", cycle_count).red().bold()
+        );
+    } else {
+        println!("  Cycles:       {}", "none".green());
+    }
+
+    // Fan-out: functions that call the most others
+    let mut fan_out: Vec<(&String, usize)> =
+        graph.adjacency.iter().map(|(k, v)| (k, v.len())).collect();
+    fan_out.sort_by(|a, b| b.1.cmp(&a.1));
+
+    if !fan_out.is_empty() {
+        println!();
+        println!("  {} (top callers):", "Fan-out".bold().underline());
+        for (name, count) in fan_out.iter().take(8) {
+            let bar_len = (*count).min(30);
+            let bar = "█".repeat(bar_len);
+            println!("    {:<40} {} {}", name.dimmed(), bar.bright_blue(), count,);
+        }
+    }
+
+    // Deepest call chains
+    println!();
+    println!(
+        "  {} (longest call chains):",
+        "Hot paths".bold().underline()
+    );
+    for entry in &graph.entry_points {
+        let depth = measure_max_depth(graph, entry, &mut HashSet::new());
+        let indicator = if depth > 6 {
+            format!("depth {}", depth).red().bold().to_string()
+        } else if depth > 3 {
+            format!("depth {}", depth).yellow().to_string()
+        } else {
+            format!("depth {}", depth).to_string()
+        };
+        println!("    {} → {}", entry.bright_white(), indicator);
+    }
+
+    println!();
+}
+
+/// Measure the maximum call depth from a given node.
+fn measure_max_depth(graph: &CallGraph, node: &str, visited: &mut HashSet<String>) -> usize {
+    if visited.contains(node) {
+        return 0;
+    }
+    visited.insert(node.to_string());
+
+    let max_child = graph
+        .adjacency
+        .get(node)
+        .map(|callees| {
+            callees
+                .iter()
+                .map(|c| measure_max_depth(graph, c, visited))
+                .max()
+                .unwrap_or(0)
+        })
+        .unwrap_or(0);
+
+    visited.remove(node);
+    1 + max_child
+}
+
+/// Public entry point: render the flow subcommand.
+pub fn render_flow(rs_files: &[PathBuf], project_path: &Path, verbose: bool) {
+    let graph = build_call_graph(rs_files, project_path);
+
+    if graph.functions.is_empty() {
+        println!("{}", "No functions found to analyze.".yellow());
+        return;
+    }
+
+    render_call_tree(&graph, verbose);
+    render_stats(&graph, verbose);
+}
+
+#[derive(Serialize)]
+struct CallEdgeJson {
+    caller: String,
+    callee: String,
+}
+
+#[derive(Serialize)]
+struct FanOutJson {
+    function: String,
+    call_count: usize,
+}
+
+#[derive(Serialize)]
+struct EntryDepthJson {
+    entry_point: String,
+    max_depth: usize,
+}
+
+#[derive(Serialize)]
+struct FlowJson {
+    cstat_version: String,
+    functions: Vec<String>,
+    call_edges: Vec<CallEdgeJson>,
+    entry_points: Vec<String>,
+    cycles: Vec<CallEdgeJson>,
+    max_depth: usize,
+    top_callers: Vec<FanOutJson>,
+    entry_depths: Vec<EntryDepthJson>,
+    cold_functions: Vec<String>,
+}
+
+/// Render flow analysis as JSON.
+pub fn render_flow_json(rs_files: &[PathBuf], project_path: &Path) {
+    let graph = build_call_graph(rs_files, project_path);
+
+    let mut call_edges = Vec::new();
+    for (caller, callees) in &graph.adjacency {
+        for callee in callees {
+            call_edges.push(CallEdgeJson {
+                caller: caller.clone(),
+                callee: callee.clone(),
+            });
+        }
+    }
+
+    let cycles: Vec<CallEdgeJson> = graph
+        .cycle_edges
+        .iter()
+        .map(|(a, b)| CallEdgeJson {
+            caller: a.clone(),
+            callee: b.clone(),
+        })
+        .collect();
+
+    let mut fan_out: Vec<(&String, usize)> =
+        graph.adjacency.iter().map(|(k, v)| (k, v.len())).collect();
+    fan_out.sort_by(|a, b| b.1.cmp(&a.1));
+    let top_callers: Vec<FanOutJson> = fan_out
+        .iter()
+        .take(20)
+        .map(|(f, c)| FanOutJson {
+            function: (*f).clone(),
+            call_count: *c,
+        })
+        .collect();
+
+    let entry_depths: Vec<EntryDepthJson> = graph
+        .entry_points
+        .iter()
+        .map(|entry| {
+            let depth = measure_max_depth(&graph, entry, &mut HashSet::new());
+            EntryDepthJson {
+                entry_point: entry.clone(),
+                max_depth: depth,
+            }
+        })
+        .collect();
+
+    let max_depth = entry_depths.iter().map(|e| e.max_depth).max().unwrap_or(0);
+
+    // Cold functions
+    let reachable = {
+        let mut reachable = HashSet::new();
+        let mut queue: Vec<String> = graph.entry_points.clone();
+        while let Some(node) = queue.pop() {
+            if !reachable.insert(node.clone()) {
+                continue;
+            }
+            if let Some(callees) = graph.adjacency.get(&node) {
+                for callee in callees {
+                    if !reachable.contains(callee) {
+                        queue.push(callee.clone());
+                    }
+                }
+            }
+        }
+        reachable
+    };
+    let cold_functions: Vec<String> = graph
+        .functions
+        .iter()
+        .filter(|f| !reachable.contains(*f))
+        .cloned()
+        .collect();
+
+    let output = FlowJson {
+        cstat_version: env!("CARGO_PKG_VERSION").to_string(),
+        functions: graph.functions,
+        call_edges,
+        entry_points: graph.entry_points,
+        cycles,
+        max_depth,
+        top_callers,
+        entry_depths,
+        cold_functions,
+    };
+
+    println!("{}", serde_json::to_string(&output).unwrap());
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/graph/algorithms.rs

@@ -0,0 +1,411 @@
+use std::collections::{HashMap, HashSet, VecDeque};
+
+// ── Generic directed graph ─────────────────────────────────────────
+
+/// A simple directed graph used for metric computation.
+pub(super) struct DiGraph {
+    pub(super) nodes: Vec<String>,
+    pub(super) adj: HashMap<String, Vec<String>>, // forward edges
+    pub(super) rev_adj: HashMap<String, Vec<String>>, // reverse edges
+}
+
+impl DiGraph {
+    pub(super) fn from_edges(nodes: Vec<String>, edges: &[(String, String)]) -> Self {
+        let mut adj: HashMap<String, Vec<String>> = HashMap::new();
+        let mut rev_adj: HashMap<String, Vec<String>> = HashMap::new();
+        for n in &nodes {
+            adj.entry(n.clone()).or_default();
+            rev_adj.entry(n.clone()).or_default();
+        }
+        for (from, to) in edges {
+            adj.entry(from.clone()).or_default().push(to.clone());
+            rev_adj.entry(to.clone()).or_default().push(from.clone());
+        }
+        DiGraph {
+            nodes,
+            adj,
+            rev_adj,
+        }
+    }
+
+    pub(super) fn node_count(&self) -> usize {
+        self.nodes.len()
+    }
+
+    pub(super) fn edge_count(&self) -> usize {
+        self.adj.values().map(|v| v.len()).sum()
+    }
+
+    pub(super) fn density(&self) -> f64 {
+        let n = self.node_count();
+        if n <= 1 {
+            return 0.0;
+        }
+        self.edge_count() as f64 / (n * (n - 1)) as f64
+    }
+}
+
+// ── Tarjan's SCC ───────────────────────────────────────────────────
+
+struct TarjanState {
+    index_counter: usize,
+    stack: Vec<String>,
+    on_stack: HashSet<String>,
+    index: HashMap<String, usize>,
+    lowlink: HashMap<String, usize>,
+    sccs: Vec<Vec<String>>,
+}
+
+pub(super) fn tarjan_scc(graph: &DiGraph) -> Vec<Vec<String>> {
+    let mut state = TarjanState {
+        index_counter: 0,
+        stack: Vec::new(),
+        on_stack: HashSet::new(),
+        index: HashMap::new(),
+        lowlink: HashMap::new(),
+        sccs: Vec::new(),
+    };
+    for node in &graph.nodes {
+        if !state.index.contains_key(node) {
+            tarjan_strongconnect(node, graph, &mut state);
+        }
+    }
+    state.sccs
+}
+
+fn tarjan_strongconnect(v: &str, graph: &DiGraph, state: &mut TarjanState) {
+    state.index.insert(v.to_string(), state.index_counter);
+    state.lowlink.insert(v.to_string(), state.index_counter);
+    state.index_counter += 1;
+    state.stack.push(v.to_string());
+    state.on_stack.insert(v.to_string());
+
+    if let Some(neighbors) = graph.adj.get(v) {
+        for w in neighbors {
+            if !state.index.contains_key(w.as_str()) {
+                tarjan_strongconnect(w, graph, state);
+                let wll = state.lowlink[w.as_str()];
+                let vll = state.lowlink.get_mut(v).unwrap();
+                if wll < *vll {
+                    *vll = wll;
+                }
+            } else if state.on_stack.contains(w.as_str()) {
+                let wi = state.index[w.as_str()];
+                let vll = state.lowlink.get_mut(v).unwrap();
+                if wi < *vll {
+                    *vll = wi;
+                }
+            }
+        }
+    }
+
+    if state.lowlink[v] == state.index[v] {
+        let mut component = Vec::new();
+        loop {
+            let w = state.stack.pop().unwrap();
+            state.on_stack.remove(&w);
+            component.push(w.clone());
+            if w == v {
+                break;
+            }
+        }
+        state.sccs.push(component);
+    }
+}
+
+// ── Brandes' betweenness centrality ────────────────────────────────
+
+/// Result of BFS forward pass from a single source.
+struct BfsResult {
+    stack: Vec<String>,
+    predecessors: HashMap<String, Vec<String>>,
+    sigma: HashMap<String, f64>,
+}
+
+/// BFS forward pass: compute shortest-path counts and predecessor lists from source `s`.
+fn bfs_shortest_paths(s: &str, graph: &DiGraph) -> BfsResult {
+    let mut stack: Vec<String> = Vec::new();
+    let mut predecessors: HashMap<String, Vec<String>> = HashMap::new();
+    let mut sigma: HashMap<String, f64> = HashMap::new();
+    let mut dist: HashMap<String, i64> = HashMap::new();
+
+    for n in &graph.nodes {
+        predecessors.insert(n.clone(), Vec::new());
+        sigma.insert(n.clone(), 0.0);
+        dist.insert(n.clone(), -1);
+    }
+    *sigma.get_mut(s).unwrap() = 1.0;
+    *dist.get_mut(s).unwrap() = 0;
+
+    let mut queue: VecDeque<String> = VecDeque::new();
+    queue.push_back(s.to_string());
+
+    while let Some(v) = queue.pop_front() {
+        stack.push(v.clone());
+        let d_v = dist[&v];
+        if let Some(neighbors) = graph.adj.get(&v) {
+            for w in neighbors {
+                if dist[w] < 0 {
+                    *dist.get_mut(w).unwrap() = d_v + 1;
+                    queue.push_back(w.clone());
+                }
+                if dist[w] == d_v + 1 {
+                    *sigma.get_mut(w).unwrap() += sigma[&v];
+                    predecessors.get_mut(w).unwrap().push(v.clone());
+                }
+            }
+        }
+    }
+
+    BfsResult {
+        stack,
+        predecessors,
+        sigma,
+    }
+}
+
+/// Back-propagation: accumulate betweenness from dependency scores.
+fn accumulate_betweenness(
+    mut stack: Vec<String>,
+    predecessors: &HashMap<String, Vec<String>>,
+    sigma: &HashMap<String, f64>,
+    s: &str,
+    cb: &mut HashMap<String, f64>,
+) {
+    let mut delta: HashMap<String, f64> = HashMap::new();
+    for n in sigma.keys() {
+        delta.insert(n.clone(), 0.0);
+    }
+
+    while let Some(w) = stack.pop() {
+        for v in &predecessors[&w] {
+            let d = sigma[v] / sigma[&w] * (1.0 + delta[&w]);
+            *delta.get_mut(v).unwrap() += d;
+        }
+        if w != s {
+            *cb.get_mut(&w).unwrap() += delta[&w];
+        }
+    }
+}
+
+pub(super) fn betweenness_centrality(graph: &DiGraph) -> HashMap<String, f64> {
+    let mut cb: HashMap<String, f64> = HashMap::new();
+    for n in &graph.nodes {
+        cb.insert(n.clone(), 0.0);
+    }
+
+    for s in &graph.nodes {
+        let bfs = bfs_shortest_paths(s, graph);
+        accumulate_betweenness(bfs.stack, &bfs.predecessors, &bfs.sigma, s, &mut cb);
+    }
+
+    // Normalize
+    let n = graph.node_count() as f64;
+    if n > 2.0 {
+        let norm = (n - 1.0) * (n - 2.0);
+        for v in cb.values_mut() {
+            *v /= norm;
+        }
+    }
+
+    cb
+}
+
+// ── PageRank ───────────────────────────────────────────────────────
+
+pub(super) fn pagerank(graph: &DiGraph, damping: f64, iterations: usize) -> HashMap<String, f64> {
+    let n = graph.node_count();
+    if n == 0 {
+        return HashMap::new();
+    }
+    let initial = 1.0 / n as f64;
+    let mut rank: HashMap<String, f64> = graph.nodes.iter().map(|n| (n.clone(), initial)).collect();
+
+    for _ in 0..iterations {
+        let mut new_rank: HashMap<String, f64> = HashMap::new();
+        let mut dangling_sum = 0.0;
+
+        for node in &graph.nodes {
+            let out_deg = graph.adj.get(node).map_or(0, |v| v.len());
+            if out_deg == 0 {
+                dangling_sum += rank[node];
+            }
+        }
+
+        for node in &graph.nodes {
+            let mut incoming_sum = 0.0;
+            if let Some(preds) = graph.rev_adj.get(node) {
+                for pred in preds {
+                    let out_deg = graph.adj.get(pred).map_or(1, |v| v.len().max(1));
+                    incoming_sum += rank[pred] / out_deg as f64;
+                }
+            }
+            let pr =
+                (1.0 - damping) / n as f64 + damping * (incoming_sum + dangling_sum / n as f64);
+            new_rank.insert(node.clone(), pr);
+        }
+        rank = new_rank;
+    }
+    rank
+}
+
+// ── Clustering coefficient ─────────────────────────────────────────
+
+/// Count directed links that exist between members of `neighbors` in the adjacency map.
+fn count_neighbor_links(neighbors: &[&str], adj: &HashMap<String, Vec<String>>) -> usize {
+    let mut links = 0usize;
+    for i in 0..neighbors.len() {
+        for j in 0..neighbors.len() {
+            if i == j {
+                continue;
+            }
+            if let Some(succs) = adj.get(neighbors[i]) {
+                if succs.iter().any(|x| x == neighbors[j]) {
+                    links += 1;
+                }
+            }
+        }
+    }
+    links
+}
+
+pub(super) fn clustering_coefficient(graph: &DiGraph) -> HashMap<String, f64> {
+    let mut cc: HashMap<String, f64> = HashMap::new();
+
+    for node in &graph.nodes {
+        // Neighbors = union of successors and predecessors
+        let mut neighbors: HashSet<&str> = HashSet::new();
+        if let Some(succs) = graph.adj.get(node) {
+            for s in succs {
+                neighbors.insert(s.as_str());
+            }
+        }
+        if let Some(preds) = graph.rev_adj.get(node) {
+            for p in preds {
+                neighbors.insert(p.as_str());
+            }
+        }
+        neighbors.remove(node.as_str());
+
+        let k = neighbors.len();
+        if k < 2 {
+            cc.insert(node.clone(), 0.0);
+            continue;
+        }
+
+        let neighbor_vec: Vec<&str> = neighbors.iter().copied().collect();
+        let links = count_neighbor_links(&neighbor_vec, &graph.adj);
+
+        let possible = k * (k - 1); // directed pairs
+        cc.insert(node.clone(), links as f64 / possible as f64);
+    }
+    cc
+}
+
+// ── Graph-level stats ──────────────────────────────────────────────
+
+pub(super) struct GraphStats {
+    pub(super) density: f64,
+    pub(super) diameter: Option<usize>,
+    pub(super) avg_path_length: f64,
+    pub(super) component_count: usize,
+}
+
+pub(super) fn graph_level_stats(graph: &DiGraph) -> GraphStats {
+    let density = graph.density();
+
+    let (diameter, avg_path_length) = if graph.node_count() <= 2000 {
+        compute_distances(graph)
+    } else {
+        (None, 0.0)
+    };
+
+    let component_count = count_weak_components(graph);
+
+    GraphStats {
+        density,
+        diameter,
+        avg_path_length,
+        component_count,
+    }
+}
+
+fn compute_distances(graph: &DiGraph) -> (Option<usize>, f64) {
+    let mut max_dist = 0usize;
+    let mut total_dist = 0u64;
+    let mut pair_count = 0u64;
+
+    for s in &graph.nodes {
+        let mut dist: HashMap<&str, usize> = HashMap::new();
+        dist.insert(s.as_str(), 0);
+        let mut queue: VecDeque<&str> = VecDeque::new();
+        queue.push_back(s.as_str());
+
+        while let Some(v) = queue.pop_front() {
+            let d = dist[v];
+            if let Some(neighbors) = graph.adj.get(v) {
+                for w in neighbors {
+                    if !dist.contains_key(w.as_str()) {
+                        let nd = d + 1;
+                        dist.insert(w.as_str(), nd);
+                        queue.push_back(w.as_str());
+                        if nd > max_dist {
+                            max_dist = nd;
+                        }
+                        total_dist += nd as u64;
+                        pair_count += 1;
+                    }
+                }
+            }
+        }
+    }
+
+    let diameter = if pair_count > 0 { Some(max_dist) } else { None };
+    let avg = if pair_count > 0 {
+        total_dist as f64 / pair_count as f64
+    } else {
+        0.0
+    };
+    (diameter, avg)
+}
+
+/// BFS traversal for one weak component starting at `start`.
+/// Visits all nodes reachable via forward or reverse edges, marking them in `visited`.
+fn bfs_weak_component<'a>(start: &'a str, graph: &'a DiGraph, visited: &mut HashSet<&'a str>) {
+    let mut queue: VecDeque<&str> = VecDeque::new();
+    queue.push_back(start);
+    visited.insert(start);
+
+    while let Some(v) = queue.pop_front() {
+        if let Some(neighbors) = graph.adj.get(v) {
+            for w in neighbors {
+                if !visited.contains(w.as_str()) {
+                    visited.insert(w.as_str());
+                    queue.push_back(w.as_str());
+                }
+            }
+        }
+        if let Some(neighbors) = graph.rev_adj.get(v) {
+            for w in neighbors {
+                if !visited.contains(w.as_str()) {
+                    visited.insert(w.as_str());
+                    queue.push_back(w.as_str());
+                }
+            }
+        }
+    }
+}
+
+fn count_weak_components(graph: &DiGraph) -> usize {
+    let mut visited: HashSet<&str> = HashSet::new();
+    let mut count = 0;
+
+    for node in &graph.nodes {
+        if visited.contains(node.as_str()) {
+            continue;
+        }
+        count += 1;
+        bfs_weak_component(node.as_str(), graph, &mut visited);
+    }
+    count
+}

src/graph/mod.rs

@@ -0,0 +1,511 @@
+mod algorithms;
+
+use colored::Colorize;
+use serde::Serialize;
+use std::collections::HashMap;
+use std::path::{Path, PathBuf};
+
+use crate::deps;
+use crate::flow;
+use crate::render;
+use algorithms::{
+    betweenness_centrality, clustering_coefficient, graph_level_stats, pagerank, tarjan_scc,
+    DiGraph, GraphStats,
+};
+
+// ── Full analysis result ───────────────────────────────────────────
+
+struct NodeMetrics {
+    betweenness: f64,
+    pagerank: f64,
+    clustering: f64,
+}
+
+struct GraphAnalysis {
+    label: String,
+    node_count: usize,
+    edge_count: usize,
+    sccs: Vec<Vec<String>>,
+    node_metrics: HashMap<String, NodeMetrics>,
+    stats: GraphStats,
+}
+
+fn analyze_graph(graph: &DiGraph, label: &str) -> GraphAnalysis {
+    let sccs = tarjan_scc(graph);
+    let bc = betweenness_centrality(graph);
+    let pr = pagerank(graph, 0.85, 100);
+    let cc = clustering_coefficient(graph);
+    let stats = graph_level_stats(graph);
+
+    let mut node_metrics: HashMap<String, NodeMetrics> = HashMap::new();
+    for node in &graph.nodes {
+        node_metrics.insert(
+            node.clone(),
+            NodeMetrics {
+                betweenness: bc.get(node).copied().unwrap_or(0.0),
+                pagerank: pr.get(node).copied().unwrap_or(0.0),
+                clustering: cc.get(node).copied().unwrap_or(0.0),
+            },
+        );
+    }
+
+    GraphAnalysis {
+        label: label.to_string(),
+        node_count: graph.node_count(),
+        edge_count: graph.edge_count(),
+        sccs,
+        node_metrics,
+        stats,
+    }
+}
+
+// ── Build DiGraph from call graph / dep graph ──────────────────────
+
+fn digraph_from_call_graph(cg: &flow::CallGraph) -> DiGraph {
+    let nodes = cg.functions.clone();
+    let mut edges = Vec::new();
+    for (caller, callees) in &cg.adjacency {
+        for callee in callees {
+            edges.push((caller.clone(), callee.clone()));
+        }
+    }
+    DiGraph::from_edges(nodes, &edges)
+}
+
+fn digraph_from_dep_analysis(da: &deps::DepAnalysis) -> DiGraph {
+    let nodes = da.modules.clone();
+    let edges: Vec<(String, String)> = da
+        .edges
+        .iter()
+        .map(|e| (e.from.clone(), e.to.clone()))
+        .collect();
+    DiGraph::from_edges(nodes, &edges)
+}
+
+// ── Rendering ──────────────────────────────────────────────────────
+
+fn render_analysis(analysis: &GraphAnalysis, top_n: usize, verbose: bool) {
+    let term_w = render::terminal_width();
+
+    let header = format!("── {} ─", analysis.label);
+    let padded = format!("{:─<width$}", header, width = 56);
+    println!("\n{}", padded.bright_cyan().bold());
+
+    render_stats_box(analysis, verbose);
+    render_sccs(analysis, verbose);
+    render_node_table(analysis, top_n, term_w, verbose);
+}
+
+fn render_stats_box(analysis: &GraphAnalysis, verbose: bool) {
+    if verbose {
+        render::verbose_block(&[
+            "Graph-level statistics for the overall structure:",
+            "  Nodes = number of functions (or modules for dependency graph).",
+            "  Edges = total directed connections between nodes.",
+            "  Density = edges / (nodes × (nodes - 1)). Ranges 0 to 1.",
+            "    Low density = sparse graph; high density = many connections.",
+            "  Components (weak) = weakly connected subgraphs (ignoring edge direction).",
+            "    >1 component = some nodes are completely isolated from others.",
+            "  Diameter = longest shortest path between any two reachable nodes.",
+            "  Avg path length = mean shortest path distance across all reachable pairs.",
+        ]);
+        render::guide_ref("architecture");
+    }
+
+    println!();
+    println!("  ┌──────────────────────────────────────┐");
+    println!(
+        "  │ {:<18} {:>17} │",
+        "Nodes".cyan(),
+        format!("{}", analysis.node_count).bold()
+    );
+    println!(
+        "  │ {:<18} {:>17} │",
+        "Edges".cyan(),
+        format!("{}", analysis.edge_count).bold()
+    );
+    println!(
+        "  │ {:<18} {:>17} │",
+        "Density".cyan(),
+        format!("{:.4}", analysis.stats.density).bold()
+    );
+    println!(
+        "  │ {:<18} {:>17} │",
+        "Components (weak)".cyan(),
+        format!("{}", analysis.stats.component_count).bold()
+    );
+    if let Some(d) = analysis.stats.diameter {
+        println!(
+            "  │ {:<18} {:>17} │",
+            "Diameter".cyan(),
+            format!("{}", d).bold()
+        );
+    }
+    if analysis.stats.avg_path_length > 0.0 {
+        println!(
+            "  │ {:<18} {:>17} │",
+            "Avg path length".cyan(),
+            format!("{:.2}", analysis.stats.avg_path_length).bold()
+        );
+    }
+    println!("  └──────────────────────────────────────┘");
+}
+
+fn render_sccs(analysis: &GraphAnalysis, verbose: bool) {
+    let cyclic_sccs: Vec<&Vec<String>> = analysis.sccs.iter().filter(|c| c.len() > 1).collect();
+
+    println!("\n  {}", "Strongly Connected Components".bold().underline());
+
+    if verbose {
+        render::verbose_block(&[
+            "SCCs found by Tarjan's algorithm: groups of mutually reachable nodes (cycles).",
+            "Every node in an SCC can reach every other node in the same SCC.",
+            "A DAG (directed acyclic graph) has no cyclic SCCs — all components are singletons.",
+            "Cyclic clusters indicate circular dependencies that may complicate refactoring.",
+        ]);
+    }
+
+    if cyclic_sccs.is_empty() {
+        println!("  {}", "No cyclic clusters found (DAG).".green());
+    } else {
+        println!(
+            "  {} cyclic cluster{}:",
+            format!("{}", cyclic_sccs.len()).red().bold(),
+            if cyclic_sccs.len() == 1 { "" } else { "s" }
+        );
+        for (i, scc) in cyclic_sccs.iter().enumerate() {
+            println!();
+            println!(
+                "    {} (size {})",
+                format!("Cluster #{}", i + 1).yellow().bold(),
+                scc.len()
+            );
+            for member in *scc {
+                println!("      {}", member.dimmed());
+            }
+        }
+    }
+}
+
+/// Render one metric section: heading, optional verbose lines, sorted bar chart.
+fn render_metric_section(
+    label: &str,
+    sorted_items: &[(&String, f64)],
+    bar_budget: usize,
+    top_n: usize,
+    verbose: bool,
+    verbose_lines: &[&str],
+) {
+    println!("\n  {}", label.bold().underline());
+
+    if verbose {
+        render::verbose_block(verbose_lines);
+    }
+
+    println!();
+    if sorted_items.is_empty() {
+        println!("    {}", "No clustering detected.".dimmed());
+        return;
+    }
+
+    let max_val = sorted_items
+        .first()
+        .map(|(_, v)| *v)
+        .unwrap_or(1.0)
+        .max(f64::MIN_POSITIVE);
+
+    for (name, val) in sorted_items.iter().take(top_n) {
+        if *val < f64::EPSILON {
+            continue;
+        }
+        let bar_len = ((*val / max_val) * bar_budget as f64).ceil() as usize;
+        let bar = "█".repeat(bar_len.max(1));
+        let ratio = (*val / max_val).min(1.0);
+        let colored_bar = render::bar_color(&bar, 1.0 - ratio);
+        println!("    {:<40} {} {:.4}", name.dimmed(), colored_bar, val,);
+    }
+}
+
+fn render_node_table(analysis: &GraphAnalysis, top_n: usize, term_w: usize, verbose: bool) {
+    if analysis.node_metrics.is_empty() {
+        return;
+    }
+
+    let bar_budget = 20.min(term_w.saturating_sub(70));
+
+    // Betweenness centrality
+    let mut bc_sorted: Vec<(&String, f64)> = analysis
+        .node_metrics
+        .iter()
+        .map(|(n, m)| (n, m.betweenness))
+        .collect();
+    bc_sorted.sort_by(|a, b| b.1.partial_cmp(&a.1).unwrap_or(std::cmp::Ordering::Equal));
+
+    render_metric_section(
+        "Betweenness Centrality (bridges/bottlenecks)",
+        &bc_sorted,
+        bar_budget,
+        top_n,
+        verbose,
+        &[
+            "Betweenness centrality (Brandes algorithm): for each node, the fraction of",
+            "all shortest paths in the graph that pass through it.",
+            "Scale: 0.0 = no shortest paths traverse this node; 1.0 = all paths do.",
+            "High bc = bridge/bottleneck — removing this node would disconnect or lengthen",
+            "paths between other parts of the graph. Normalized by (n-1)(n-2).",
+            "Bar length proportional to highest bc value. Color: red = top, green = low.",
+        ],
+    );
+
+    // PageRank
+    let mut pr_sorted: Vec<(&String, f64)> = analysis
+        .node_metrics
+        .iter()
+        .map(|(n, m)| (n, m.pagerank))
+        .collect();
+    pr_sorted.sort_by(|a, b| b.1.partial_cmp(&a.1).unwrap_or(std::cmp::Ordering::Equal));
+
+    render_metric_section(
+        "PageRank (recursive importance)",
+        &pr_sorted,
+        bar_budget,
+        top_n,
+        verbose,
+        &[
+            "PageRank: iterative importance score. A node is important if important nodes",
+            "point to it. Damping factor = 0.85, 100 iterations.",
+            "Dangling nodes (no outgoing edges) distribute their rank uniformly.",
+            "Higher value = more central/important in the call graph.",
+            "All PageRank values sum to 1.0 across the entire graph.",
+        ],
+    );
+
+    // Clustering coefficient
+    let mut cc_sorted: Vec<(&String, f64)> = analysis
+        .node_metrics
+        .iter()
+        .map(|(n, m)| (n, m.clustering))
+        .filter(|(_, v)| *v > f64::EPSILON)
+        .collect();
+    cc_sorted.sort_by(|a, b| b.1.partial_cmp(&a.1).unwrap_or(std::cmp::Ordering::Equal));
+
+    render_metric_section(
+        "Clustering Coefficient (neighborhood density)",
+        &cc_sorted,
+        bar_budget,
+        top_n,
+        verbose,
+        &[
+            "Clustering coefficient: for each node, the fraction of its neighbors that",
+            "are also connected to each other. Neighbors = union of successors and predecessors.",
+            "Scale: 0.0 = none of the node's neighbors know each other; 1.0 = complete clique.",
+            "High cc = tight neighborhood cluster. Low cc = broker between different groups.",
+            "Only nodes with cc > 0 are shown.",
+        ],
+    );
+
+    println!();
+}
+
+// ── Public entry point ─────────────────────────────────────────────
+
+/// Compact summary data for embedding in the dashboard.
+pub struct GraphSummary {
+    /// Node with highest betweenness centrality (bridge).
+    pub top_bridge: Option<(String, f64)>,
+    /// Node with highest PageRank (hub).
+    pub top_hub: Option<(String, f64)>,
+    /// Node with highest clustering coefficient.
+    pub top_clustered: Option<(String, f64)>,
+}
+
+/// Compute compact graph summary from the call graph for dashboard use.
+pub fn graph_summary(rs_files: &[PathBuf], project_path: &Path) -> Option<GraphSummary> {
+    let cg = flow::build_call_graph(rs_files, project_path);
+    if cg.functions.is_empty() {
+        return None;
+    }
+    let dg = digraph_from_call_graph(&cg);
+    let analysis = analyze_graph(&dg, "");
+
+    let top_bridge = analysis
+        .node_metrics
+        .iter()
+        .filter(|(_, m)| m.betweenness > f64::EPSILON)
+        .max_by(|a, b| {
+            a.1.betweenness
+                .partial_cmp(&b.1.betweenness)
+                .unwrap_or(std::cmp::Ordering::Equal)
+        })
+        .map(|(n, m)| (n.clone(), m.betweenness));
+
+    let top_hub = analysis
+        .node_metrics
+        .iter()
+        .max_by(|a, b| {
+            a.1.pagerank
+                .partial_cmp(&b.1.pagerank)
+                .unwrap_or(std::cmp::Ordering::Equal)
+        })
+        .map(|(n, m)| (n.clone(), m.pagerank));
+
+    let top_clustered = analysis
+        .node_metrics
+        .iter()
+        .filter(|(_, m)| m.clustering > f64::EPSILON)
+        .max_by(|a, b| {
+            a.1.clustering
+                .partial_cmp(&b.1.clustering)
+                .unwrap_or(std::cmp::Ordering::Equal)
+        })
+        .map(|(n, m)| (n.clone(), m.clustering));
+
+    Some(GraphSummary {
+        top_bridge,
+        top_hub,
+        top_clustered,
+    })
+}
+
+pub fn render_graph(
+    rs_files: &[PathBuf],
+    project_path: &Path,
+    call_only: bool,
+    dep_only: bool,
+    top_n: usize,
+    verbose: bool,
+) {
+    if !dep_only {
+        let cg = flow::build_call_graph(rs_files, project_path);
+        if cg.functions.is_empty() {
+            println!("{}", "No functions found for call graph analysis.".yellow());
+        } else {
+            let dg = digraph_from_call_graph(&cg);
+            let analysis = analyze_graph(&dg, "Call Graph Analysis");
+            render_analysis(&analysis, top_n, verbose);
+        }
+    }
+
+    if !call_only {
+        let da = deps::analyze_deps(rs_files, project_path);
+        if da.modules.is_empty() {
+            println!(
+                "{}",
+                "No modules found for dependency graph analysis.".yellow()
+            );
+        } else {
+            let dg = digraph_from_dep_analysis(&da);
+            let analysis = analyze_graph(&dg, "Module Dependency Graph Analysis");
+            render_analysis(&analysis, top_n, verbose);
+        }
+    }
+}
+
+// ── JSON Output ────────────────────────────────────────────────────
+
+#[derive(Serialize)]
+struct NodeMetricsJson {
+    node: String,
+    betweenness: f64,
+    pagerank: f64,
+    clustering: f64,
+}
+
+#[derive(Serialize)]
+struct GraphStatsJson {
+    density: f64,
+    diameter: Option<usize>,
+    avg_path_length: f64,
+    component_count: usize,
+}
+
+#[derive(Serialize)]
+struct GraphAnalysisJson {
+    label: String,
+    node_count: usize,
+    edge_count: usize,
+    sccs: Vec<Vec<String>>,
+    node_metrics: Vec<NodeMetricsJson>,
+    stats: GraphStatsJson,
+}
+
+#[derive(Serialize)]
+struct GraphOutputJson {
+    cstat_version: String,
+    call_graph: Option<GraphAnalysisJson>,
+    dep_graph: Option<GraphAnalysisJson>,
+}
+
+fn analysis_to_json(analysis: &GraphAnalysis) -> GraphAnalysisJson {
+    let mut node_metrics: Vec<NodeMetricsJson> = analysis
+        .node_metrics
+        .iter()
+        .map(|(n, m)| NodeMetricsJson {
+            node: n.clone(),
+            betweenness: m.betweenness,
+            pagerank: m.pagerank,
+            clustering: m.clustering,
+        })
+        .collect();
+    node_metrics.sort_by(|a, b| {
+        b.betweenness
+            .partial_cmp(&a.betweenness)
+            .unwrap_or(std::cmp::Ordering::Equal)
+    });
+
+    GraphAnalysisJson {
+        label: analysis.label.clone(),
+        node_count: analysis.node_count,
+        edge_count: analysis.edge_count,
+        sccs: analysis.sccs.clone(),
+        node_metrics,
+        stats: GraphStatsJson {
+            density: analysis.stats.density,
+            diameter: analysis.stats.diameter,
+            avg_path_length: analysis.stats.avg_path_length,
+            component_count: analysis.stats.component_count,
+        },
+    }
+}
+
+/// Render graph analysis as JSON.
+pub fn render_graph_json(
+    rs_files: &[PathBuf],
+    project_path: &Path,
+    call_only: bool,
+    dep_only: bool,
+) {
+    let call_graph_json = if !dep_only {
+        let cg = flow::build_call_graph(rs_files, project_path);
+        if cg.functions.is_empty() {
+            None
+        } else {
+            let dg = digraph_from_call_graph(&cg);
+            let analysis = analyze_graph(&dg, "Call Graph Analysis");
+            Some(analysis_to_json(&analysis))
+        }
+    } else {
+        None
+    };
+
+    let dep_graph_json = if !call_only {
+        let da = deps::analyze_deps(rs_files, project_path);
+        if da.modules.is_empty() {
+            None
+        } else {
+            let dg = digraph_from_dep_analysis(&da);
+            let analysis = analyze_graph(&dg, "Module Dependency Graph Analysis");
+            Some(analysis_to_json(&analysis))
+        }
+    } else {
+        None
+    };
+
+    let output = GraphOutputJson {
+        cstat_version: env!("CARGO_PKG_VERSION").to_string(),
+        call_graph: call_graph_json,
+        dep_graph: dep_graph_json,
+    };
+
+    println!("{}", serde_json::to_string(&output).unwrap());
+}

src/guide.rs

@@ -0,0 +1,467 @@
+use colored::Colorize;
+use serde::Serialize;
+
+// ── Topic definitions ──────────────────────────────────────────────
+
+pub const TOPICS: &[(&str, &str)] = &[
+    (
+        "getting-started",
+        "First steps: reading your codebase with cstat",
+    ),
+    ("size", "File and function size, LoC distribution"),
+    (
+        "complexity",
+        "Cyclomatic, cognitive, nesting, parameter metrics",
+    ),
+    (
+        "modularity",
+        "Coupling, cohesion, dependency structure, circuits",
+    ),
+    ("flow", "Call graph, reachability, dead code, hot paths"),
+    ("redundancy", "Similar and duplicate function detection"),
+    (
+        "architecture",
+        "Centrality, SCCs, hubs, tiers, graph topology",
+    ),
+];
+
+struct TopicContent {
+    description: &'static str,
+    metrics: &'static [(&'static str, &'static str)],
+    commands: &'static [&'static str],
+    patterns: &'static [&'static str],
+}
+
+fn topic_getting_started() -> TopicContent {
+    TopicContent {
+        description: "\
+cstat analyzes Rust codebases along several dimensions — size, complexity, \
+dependency structure, call flow, and duplication — then surfaces observations \
+about what it finds. Start with `cstat summary` for a human-readable dashboard, \
+or `cstat dump` for a machine-readable JSON diagnostic report.",
+        metrics: &[
+            ("summary dashboard", "Compact overview of all dimensions with key stats"),
+            ("dump report", "Full JSON diagnostic with health scores, observations, hotspots, and topology"),
+            ("health scores", "Normalized 0.0–1.0 scores for modularity, complexity, and maintainability (higher = healthier)"),
+        ],
+        commands: &[
+            "cstat summary           — human-readable dashboard (default command)",
+            "cstat summary -v        — dashboard with educational explanations",
+            "cstat dump              — machine-readable JSON diagnostic report",
+            "cstat <command> --json  — structured JSON output for any command",
+        ],
+        patterns: &[
+            "Human workflow: run summary first, read the dashboard, drill into specific \
+dimensions with loc/branching/signature/span/deps/flow/graph as needed.",
+            "Agent workflow: run dump for the full diagnostic picture, read scores to \
+identify weak dimensions, use individual commands with --json to explore specifics.",
+            "The -v (verbose) flag adds contextual explanations to any command — useful \
+when learning what the metrics mean.",
+        ],
+    }
+}
+
+fn topic_size() -> TopicContent {
+    TopicContent {
+        description: "\
+Size metrics measure the volume and distribution of Rust source. `cstat loc` owns the line-count contract; run `cstat loc --explain` for modes, code_lines rules, and JSON fields.",
+        metrics: &[
+            (
+                "file size shape",
+                "Project-level file-size distribution from `cstat loc --path .`.",
+            ),
+            (
+                "selected-file line reachability",
+                "Projected static reachable/unreachable production spans from `cstat loc --path <file.rs>`.",
+            ),
+            (
+                "distribution statistics",
+                "Mean, median, std_dev, min, and max summarize project file sizes.",
+            ),
+        ],
+        commands: &[
+            "cstat loc --explain       — loc modes, code_lines rules, and JSON field contract",
+            "cstat loc --path .        — project size-shape report",
+            "cstat loc --path src/lib.rs — selected-file projected line reachability",
+            "cstat dist --metric loc — histogram and outlier analysis of LoC distribution",
+        ],
+        patterns: &[
+            "Use `cstat loc --explain` as the canonical reference before consuming loc output.",
+            "A right-skewed project-mode code_lines distribution means a few files dominate size.",
+            "Selected-file loc is a static projection from function spans and test/benchmark reachability; do not read it as runtime coverage.",
+        ],
+    }
+}
+
+fn topic_complexity() -> TopicContent {
+    TopicContent {
+        description: "\
+Complexity metrics are split by question: branching for decision/path shape, \
+signature for API-boundary difficulty, and span for function-local implementation \
+size. No single metric captures the full picture — cyclomatic counts paths, \
+cognitive models reading difficulty in diagnostics/distributions, nesting measures \
+structural depth, and parameter count reflects interface width.",
+        metrics: &[
+            ("cyclomatic complexity", "Number of linearly independent paths through a function (branch_points + 1). Higher values mean more test cases needed for full coverage."),
+            ("cognitive complexity", "SonarSource model: +1 per control flow break, +nesting_level penalty. Used by diagnostics/distributions, not exposed as a top-level probe."),
+            ("nesting depth", "Maximum depth of nested control structures. Deep nesting forces readers to hold more context in working memory."),
+            ("parameter count", "Number of function parameters. Wide interfaces are harder to call correctly and may indicate a function doing too much."),
+            ("function span", "Inclusive function-local line range and top-level body statement count. This complements file/project LOC."),
+        ],
+        commands: &[
+            "cstat branching        — decision/path complexity by function",
+            "cstat signature        — API-boundary complexity by function and file",
+            "cstat span             — function-local implementation size and line ranges",
+            "cstat advanced dist --metric cyclomatic — distribution and outlier analysis",
+        ],
+        patterns: &[
+            "High cyclomatic but low cognitive complexity usually means straightforward \
+branching (e.g. match statements with simple arms). High cognitive with \
+moderate cyclomatic often means nested conditionals.",
+            "Functions with nesting depth > 4 are nearly always worth refactoring — \
+extract inner blocks into helper functions to flatten the structure.",
+            "Use branching, signature, and span together: a function can be easy to call \
+but branch-heavy, short but hard to satisfy generically, or long without many decisions.",
+        ],
+    }
+}
+
+fn topic_modularity() -> TopicContent {
+    TopicContent {
+        description: "\
+Modularity metrics describe the dependency structure between modules — how \
+tightly they are coupled to each other and how cohesive each module is \
+internally. Good modularity means changes tend to stay local rather than \
+rippling across the codebase.",
+        metrics: &[
+            ("fan-in", "Number of modules that depend on this module. High fan-in modules are foundational — changes to them have wide impact."),
+            ("fan-out", "Number of modules this module depends on. High fan-out may indicate a module that coordinates too many concerns."),
+            ("bidirectional coupling", "Module pairs that depend on each other. Often a sign that the modules should be merged or the interface redesigned."),
+            ("call cohesion", "Fraction of a module's functions that call at least one other function in the same module. Low values suggest the module groups unrelated functionality."),
+            ("type cohesion", "Fraction of functions sharing parameter or return types with siblings. Measures data-level relatedness."),
+            ("modularity Q", "Graph-theoretic partition quality from community detection. Higher values indicate well-separated clusters."),
+        ],
+        commands: &[
+            "cstat deps              — module dependency graph with coupling and cohesion",
+            "cstat deps --json       — structured dependency and cohesion data",
+            "cstat circuits          — community detection showing functional clusters",
+            "cstat circuits --json   — structured circuit membership data",
+        ],
+        patterns: &[
+            "Bidirectional coupling pairs are the highest-priority modularity issue. \
+They create change amplification — modifying either module risks breaking \
+the other.",
+            "A module with high fan-in AND high fan-out is a potential god module — it \
+both serves many consumers and depends on many providers.",
+            "Low cohesion (< 0.3) combined with large file size strongly suggests the \
+module bundles unrelated concerns. Check if its functions form distinct \
+clusters using `cstat circuits`.",
+        ],
+    }
+}
+
+fn topic_flow() -> TopicContent {
+    TopicContent {
+        description: "\
+Flow analysis maps the call graph — which functions call which others — and \
+uses it to identify entry points, dead code, hot paths, and structural \
+properties of execution flow. This is static analysis; it shows what *can* \
+be called, not runtime frequency.",
+        metrics: &[
+            ("entry points", "Functions reachable as starting points: main() and #[test] functions."),
+            ("reachable functions", "Functions reachable from any entry point via the call graph."),
+            ("cold functions", "Functions with zero incoming calls. May be dead code, or may be entry points for external consumers."),
+            ("max call depth", "Longest chain of function calls. Very deep chains can indicate over-decomposition or recursion."),
+            ("coverage", "Percentage of functions reachable from entry points. Low coverage means much of the code may be unused."),
+            ("hot paths", "Paths through the call graph that visit the most functions. Shows the main execution spine."),
+        ],
+        commands: &[
+            "cstat flow                     — call graph edges, entry points, cycles, cold functions",
+            "cstat flow --json              — structured call graph data",
+            "cstat test-reachability        — static test/benchmark reachability",
+            "cstat test-reachability --json — structured test/benchmark reachability data",
+            "cstat advanced flow-heatmap       — legacy random-walk heatmap",
+            "cstat advanced flow-heatmap --json — structured visit counts and hot paths",
+        ],
+        patterns: &[
+            "Cold functions that are not pub items or test helpers are likely dead code. \
+Verify by checking if they appear in the module's public interface.",
+            "Cycles in the call graph (recursive or mutually recursive functions) are \
+worth noting — they make reasoning about termination harder and can cause \
+stack overflows.",
+            "Low coverage (< 70%) may indicate modules that are libraries consumed \
+externally, or it may indicate accumulated dead code.",
+        ],
+    }
+}
+
+fn topic_redundancy() -> TopicContent {
+    TopicContent {
+        description: "\
+Redundancy detection identifies functions that are structurally or \
+signature-similar to each other. Duplicated logic is a maintenance burden — \
+bug fixes need to be applied in multiple places, and divergent copies create \
+subtle inconsistencies.",
+        metrics: &[
+            ("signature similarity", "Compares function name, parameter types, and return type. High similarity suggests functions that evolved from copy-paste."),
+            ("structural similarity", "Normalizes function ASTs (strips identifiers, collapses literals) and compares hashes. Catches duplicates even when variable names differ."),
+            ("similarity score", "Combined score from 0.0 to 1.0. Above 0.7 is suspicious; above 0.9 is near-certain duplication."),
+            ("similarity kind", "Whether the match is by signature, structure, or both. 'Both' matches are the strongest signal."),
+        ],
+        commands: &[
+            "cstat redundancy        — table of suspected duplicate function pairs",
+            "cstat redundancy --json — structured similarity data for all pairs",
+        ],
+        patterns: &[
+            "Structural duplicates with different names often indicate utility functions \
+that were independently implemented in different modules. Consider extracting \
+to a shared location.",
+            "Signature-only matches (same parameter/return types, similar names) may be \
+intentional polymorphism or may indicate an interface that should be a trait.",
+            "A high count of redundant pairs in a single module suggests the module grew \
+by accretion rather than design.",
+        ],
+    }
+}
+
+fn topic_architecture() -> TopicContent {
+    TopicContent {
+        description: "\
+Architecture metrics apply graph theory to the call graph and dependency \
+graph to reveal structural properties invisible at the function level — \
+bridges, hubs, clusters, and overall connectivity patterns. These metrics \
+describe the shape of the codebase.",
+        metrics: &[
+            ("betweenness centrality", "How often a node lies on shortest paths between other nodes. High-betweenness nodes are bridges — their removal disconnects the graph."),
+            ("PageRank", "Recursive importance: a node is important if important nodes point to it. Identifies the most depended-upon functions."),
+            ("SCCs (strongly connected components)", "Groups of nodes where every node can reach every other. In a call graph, these are mutual recursion groups. In a dependency graph, these are cyclic dependency clusters."),
+            ("clustering coefficient", "How densely connected a node's neighbors are to each other. High values mean tight local clusters; low values mean the node bridges separate groups."),
+            ("graph density", "Ratio of actual edges to possible edges. Very low density means a sparse, tree-like structure; higher density means more interconnection."),
+        ],
+        commands: &[
+            "cstat graph             — SCC analysis, centrality, PageRank, clustering",
+            "cstat graph --json      — structured graph metrics",
+            "cstat graph --call-only — analyze only the call graph",
+            "cstat graph --dep-only  — analyze only the module dependency graph",
+            "cstat map               — architectural tier visualization",
+        ],
+        patterns: &[
+            "High-betweenness nodes are refactoring leverage points: splitting them can \
+decouple large portions of the codebase.",
+            "Large SCCs in the dependency graph indicate tightly coupled module groups. \
+These tend to grow over time as dependencies accumulate.",
+            "A hub (high PageRank + high fan-out) that is also a bridge (high betweenness) \
+is a critical risk point — it is both heavily depended upon and structurally \
+load-bearing.",
+        ],
+    }
+}
+
+fn topic_content(name: &str) -> Option<TopicContent> {
+    match name {
+        "getting-started" => Some(topic_getting_started()),
+        "size" => Some(topic_size()),
+        "complexity" => Some(topic_complexity()),
+        "modularity" => Some(topic_modularity()),
+        "flow" => Some(topic_flow()),
+        "redundancy" => Some(topic_redundancy()),
+        "architecture" => Some(topic_architecture()),
+        _ => None,
+    }
+}
+
+// ── JSON serialization ─────────────────────────────────────────────
+
+#[derive(Serialize)]
+struct GuideTocJson {
+    cstat_version: String,
+    topics: Vec<GuideTopicEntry>,
+}
+
+#[derive(Serialize)]
+struct GuideTopicEntry {
+    name: String,
+    summary: String,
+}
+
+#[derive(Serialize)]
+struct GuideTopicJson {
+    cstat_version: String,
+    topic: String,
+    description: String,
+    metrics: Vec<GuideMetricJson>,
+    commands: Vec<String>,
+    patterns: Vec<String>,
+}
+
+#[derive(Serialize)]
+struct GuideMetricJson {
+    name: String,
+    description: String,
+}
+
+// ── Public interface ───────────────────────────────────────────────
+
+/// Render the guide table of contents (no topic specified).
+pub fn render_guide_toc(json: bool) {
+    if json {
+        render_guide_toc_json();
+    } else {
+        render_guide_toc_human();
+    }
+}
+
+/// Render a specific guide topic.
+pub fn render_guide_topic(topic: &str, json: bool) {
+    if json {
+        render_guide_topic_json(topic);
+    } else {
+        render_guide_topic_human(topic);
+    }
+}
+
+// ── Human-readable rendering ───────────────────────────────────────
+
+fn render_guide_toc_human() {
+    println!();
+    println!(
+        "{}",
+        "cstat guide — code health reference".bright_cyan().bold()
+    );
+    println!();
+    for (name, summary) in TOPICS {
+        println!("  {:<18}{}", name.bold(), summary);
+    }
+    println!();
+    println!("Run: {}", "cstat guide <topic>".white().bold());
+    println!();
+}
+
+fn render_guide_topic_human(name: &str) {
+    let content = match topic_content(name) {
+        Some(c) => c,
+        None => {
+            eprintln!("Unknown guide topic: {}", name);
+            eprintln!();
+            eprintln!("Available topics:");
+            for (t, _) in TOPICS {
+                eprintln!("  {}", t);
+            }
+            std::process::exit(1);
+        }
+    };
+
+    let topic_summary = TOPICS
+        .iter()
+        .find(|(n, _)| *n == name)
+        .map(|(_, s)| *s)
+        .unwrap_or("");
+
+    println!();
+    println!(
+        "{} — {}",
+        format!("cstat guide {}", name).bright_cyan().bold(),
+        topic_summary
+    );
+
+    // Description
+    println!();
+    for line in content.description.lines() {
+        println!("  {}", line);
+    }
+
+    // Metrics
+    if !content.metrics.is_empty() {
+        println!();
+        println!("{}", "  Key metrics:".bold());
+        for (metric, desc) in content.metrics {
+            println!();
+            println!("    {}", metric.yellow().bold());
+            // Wrap description text
+            for line in desc.lines() {
+                println!("      {}", line);
+            }
+        }
+    }
+
+    // Commands
+    if !content.commands.is_empty() {
+        println!();
+        println!("{}", "  Relevant commands:".bold());
+        for cmd in content.commands {
+            println!("    {}", cmd.dimmed());
+        }
+    }
+
+    // Patterns
+    if !content.patterns.is_empty() {
+        println!();
+        println!("{}", "  Patterns worth noticing:".bold());
+        for pattern in content.patterns {
+            println!();
+            print!("    • ");
+            // Simple word-wrap at ~72 chars for readability
+            let words: Vec<&str> = pattern.split_whitespace().collect();
+            let mut col = 6; // indent of "    • "
+            for (i, word) in words.iter().enumerate() {
+                if i > 0 && col + 1 + word.len() > 76 {
+                    println!();
+                    print!("      ");
+                    col = 6;
+                } else if i > 0 {
+                    print!(" ");
+                    col += 1;
+                }
+                print!("{}", word);
+                col += word.len();
+            }
+            println!();
+        }
+    }
+
+    println!();
+}
+
+// ── JSON rendering ─────────────────────────────────────────────────
+
+fn render_guide_toc_json() {
+    let output = GuideTocJson {
+        cstat_version: env!("CARGO_PKG_VERSION").to_string(),
+        topics: TOPICS
+            .iter()
+            .map(|(name, summary)| GuideTopicEntry {
+                name: name.to_string(),
+                summary: summary.to_string(),
+            })
+            .collect(),
+    };
+    println!("{}", serde_json::to_string(&output).unwrap());
+}
+
+fn render_guide_topic_json(name: &str) {
+    let content = match topic_content(name) {
+        Some(c) => c,
+        None => {
+            let err = serde_json::json!({"error": format!("Unknown guide topic: {}", name)});
+            println!("{}", serde_json::to_string(&err).unwrap());
+            std::process::exit(1);
+        }
+    };
+
+    let output = GuideTopicJson {
+        cstat_version: env!("CARGO_PKG_VERSION").to_string(),
+        topic: name.to_string(),
+        description: content.description.to_string(),
+        metrics: content
+            .metrics
+            .iter()
+            .map(|(n, d)| GuideMetricJson {
+                name: n.to_string(),
+                description: d.to_string(),
+            })
+            .collect(),
+        commands: content.commands.iter().map(|s| s.to_string()).collect(),
+        patterns: content.patterns.iter().map(|s| s.to_string()).collect(),
+    };
+    println!("{}", serde_json::to_string(&output).unwrap());
+}

src/main.rs

@@ -1,17 +1,27 @@
 mod ast_parser;
 mod call_trace;
+mod circuits;
 mod cluster;
 mod complexity;
 mod coverage;
 mod datapaths;
 mod dead_code;
 mod deps;
+mod diagnostics;
 mod discovery;
+mod dist;
+mod dump;
 mod file_metrics;
+mod file_summary;
 mod flow;
+mod graph;
+mod guide;
 mod loc;
+mod map;
+mod redundancy;
 mod render;
-mod scorecard;
+mod report;
+mod summary;
 mod symbols;
 
 use clap::{Parser, Subcommand};
@@ -21,7 +31,7 @@ use std::path::PathBuf;
 #[command(name = "cstat", about = "Rust codebase complexity analyzer")]
 struct Cli {
     #[command(subcommand)]
-    command: Commands,
+    command: Option<Commands>,
 
     /// Rust project directory or Rust source file to analyze (defaults to current directory)
     #[arg(long, default_value = ".", global = true)]
@@ -42,6 +52,10 @@ struct Cli {
 
 #[derive(Subcommand)]
 enum Commands {
+    /// Focused module metrics report (default)
+    Summary,
+    /// Alias for the focused module metrics report
+    Report,
     #[command(
         about = "Lines-of-code size-shape analysis",
         long_about = r#"Lines-of-code size-shape analysis for Rust source.
@@ -85,12 +99,6 @@ Use --explain to print this usage and JSON field contract without running analys
     Signature,
     /// Function implementation span rankings
     Span,
-    /// Deterministic structural code complexity scorecard
-    Scorecard {
-        /// Show only the top N contributors
-        #[arg(long)]
-        top: Option<usize>,
-    },
     /// Module dependency connectome
     Deps {
         /// Show only the top N most connected modules
@@ -115,6 +123,66 @@ Use --explain to print this usage and JSON field contract without running analys
     },
     /// Value-cluster transcript from AST def-use structure.
     Cluster,
+    /// Opt-in legacy and exploratory analyses
+    Advanced {
+        #[command(subcommand)]
+        command: AdvancedCommands,
+    },
+}
+
+#[derive(Subcommand)]
+enum AdvancedCommands {
+    /// Previous broad dashboard overview
+    Summary,
+    /// Bird's eye module map — architectural overview
+    Map,
+    /// Static call graph / execution flow analysis
+    Flow,
+    /// Graph-theoretic analysis (SCCs, centrality, PageRank, clustering)
+    Graph {
+        /// Analyze only the call graph
+        #[arg(long)]
+        call_only: bool,
+        /// Analyze only the module dependency graph
+        #[arg(long)]
+        dep_only: bool,
+        /// Show only the top N nodes per metric
+        #[arg(long, default_value = "10")]
+        top: usize,
+    },
+    /// Previous random-walk execution flow heatmap
+    FlowHeatmap {
+        /// Number of random walks to simulate
+        #[arg(long, default_value = "10000")]
+        walks: usize,
+        /// Start from a specific function instead of all entry points
+        #[arg(long, name = "FUNCTION")]
+        from: Option<String>,
+    },
+    /// Distribution visualizations (histograms, scatter, outliers, correlations)
+    Dist {
+        /// Show only a single metric (loc, cyclomatic, cognitive, nesting, params)
+        #[arg(long)]
+        metric: Option<String>,
+        /// Number of histogram bins
+        #[arg(long, default_value = "10")]
+        bins: usize,
+    },
+    /// Functional cluster decomposition via community detection
+    Circuits {
+        /// Minimum circuit size to display
+        #[arg(long, default_value = "1")]
+        min_size: usize,
+    },
+    /// Detect suspected duplicate or near-duplicate functions
+    Redundancy,
+    /// Machine-readable diagnostic summary (always JSON)
+    Dump,
+    /// Code health reference — topic-based workflow and metric guide
+    Guide {
+        /// Topic to display (e.g. getting-started, size, complexity, modularity, flow, redundancy, architecture)
+        topic: Option<String>,
+    },
 }
 
 fn main() {
@@ -127,13 +195,12 @@ fn main() {
     }
 
     let verbose = cli.verbose;
-    let command = cli.command;
+    let command = cli.command.unwrap_or(Commands::Summary);
 
     if let Commands::Loc { explain: true, .. } = &command {
         loc::render_loc_explain(json);
         return;
     }
-
     let target = match discovery::resolve_target(&cli.path) {
         Ok(target) => target,
         Err(e) => {
@@ -153,6 +220,18 @@ fn main() {
         let project_rs_files = discovery::files_for_project(&target);
         let target_rs_files = discovery::files_for_target(&target);
         match command {
+            Commands::Summary | Commands::Report => {
+                if json {
+                    file_summary::render_file_summary_json(project_rs_files, project_path, file);
+                } else {
+                    file_summary::render_file_summary(
+                        project_rs_files,
+                        project_path,
+                        file,
+                        verbose,
+                    );
+                }
+            }
             Commands::Loc { .. } => {
                 if json {
                     loc::render_loc_file_json(project_rs_files, project_path, file);
@@ -183,16 +262,6 @@ fn main() {
                     cluster::render_cluster_file(project_rs_files, project_path, file, verbose);
                 }
             }
-            Commands::Scorecard { top } => {
-                scorecard::render_scorecard(
-                    target_rs_files,
-                    project_path,
-                    &cli.path.display().to_string(),
-                    top,
-                    json,
-                    verbose,
-                );
-            }
             Commands::Deps { .. } => {
                 if json {
                     deps::render_deps_file_json(project_rs_files, project_path, file);
@@ -248,7 +317,6 @@ fn main() {
                     Some(file),
                     no_run,
                     json,
-                    verbose,
                 ) {
                     if json {
                         let err = serde_json::json!({"error": message});
@@ -259,11 +327,29 @@ fn main() {
                     std::process::exit(1);
                 }
             }
+            Commands::Advanced { .. } => {
+                let message =
+                    "advanced commands require a project directory; pass --path <crate-dir>";
+                if json {
+                    let err = serde_json::json!({"error": message});
+                    println!("{}", serde_json::to_string(&err).unwrap());
+                } else {
+                    eprintln!("Error: {}", message);
+                }
+                std::process::exit(1);
+            }
         }
         return;
     }
 
     match command {
+        Commands::Summary | Commands::Report => {
+            if json {
+                report::render_report_json(&rs_files, &project_path);
+            } else {
+                report::render_report(&rs_files, &project_path, verbose);
+            }
+        }
         Commands::Loc { top, .. } => {
             if json {
                 loc::render_loc_json(&rs_files, &project_path);
@@ -287,16 +373,6 @@ fn main() {
         Commands::Span => {
             complexity::run_span(&rs_files, &project_path, json, verbose);
         }
-        Commands::Scorecard { top } => {
-            scorecard::render_scorecard(
-                &rs_files,
-                &project_path,
-                &cli.path.display().to_string(),
-                top,
-                json,
-                verbose,
-            );
-        }
         Commands::Cluster => {
             cluster::render_cluster(&rs_files, &project_path, json, verbose);
         }
@@ -336,7 +412,7 @@ fn main() {
         }
         Commands::Coverage { no_run } => {
             if let Err(message) =
-                coverage::render_coverage(&rs_files, &project_path, None, no_run, json, verbose)
+                coverage::render_coverage(&rs_files, &project_path, None, no_run, json)
             {
                 if json {
                     let err = serde_json::json!({"error": message});
@@ -347,5 +423,93 @@ fn main() {
                 std::process::exit(1);
             }
         }
+        Commands::Advanced { command } => match command {
+            AdvancedCommands::Summary => {
+                if json {
+                    summary::render_summary_json(&rs_files, &project_path);
+                } else {
+                    summary::render_summary(&rs_files, &project_path, verbose);
+                }
+            }
+            AdvancedCommands::Map => {
+                if json {
+                    map::render_map_json(&rs_files, &project_path);
+                } else {
+                    map::render_map(&rs_files, &project_path, verbose);
+                }
+            }
+            AdvancedCommands::Flow => {
+                if json {
+                    flow::render_flow_json(&rs_files, &project_path);
+                } else {
+                    flow::render_flow(&rs_files, &project_path, verbose);
+                }
+            }
+            AdvancedCommands::Graph {
+                call_only,
+                dep_only,
+                top,
+            } => {
+                if json {
+                    graph::render_graph_json(&rs_files, &project_path, call_only, dep_only);
+                } else {
+                    graph::render_graph(
+                        &rs_files,
+                        &project_path,
+                        call_only,
+                        dep_only,
+                        top,
+                        verbose,
+                    );
+                }
+            }
+            AdvancedCommands::FlowHeatmap { walks, from } => {
+                if json {
+                    datapaths::render_datapaths_json(
+                        &rs_files,
+                        &project_path,
+                        walks,
+                        from.as_deref(),
+                    );
+                } else {
+                    datapaths::render_datapaths(
+                        &rs_files,
+                        &project_path,
+                        walks,
+                        from.as_deref(),
+                        verbose,
+                    );
+                }
+            }
+            AdvancedCommands::Dist { metric, bins } => {
+                if json {
+                    dist::render_dist_json(&rs_files, &project_path, metric.as_deref(), bins);
+                } else {
+                    dist::render_dist(&rs_files, &project_path, metric.as_deref(), bins, verbose);
+                }
+            }
+            AdvancedCommands::Circuits { min_size } => {
+                if json {
+                    circuits::render_circuits_json(&rs_files, &project_path, min_size);
+                } else {
+                    circuits::render_circuits(&rs_files, &project_path, min_size, verbose);
+                }
+            }
+            AdvancedCommands::Redundancy => {
+                if json {
+                    redundancy::render_redundancy_json(&rs_files, &project_path);
+                } else {
+                    redundancy::render_redundancy(&rs_files, &project_path, verbose);
+                }
+            }
+            AdvancedCommands::Dump => {
+                colored::control::set_override(false);
+                dump::render_dump(&rs_files, &project_path);
+            }
+            AdvancedCommands::Guide { topic } => match topic {
+                Some(t) => guide::render_guide_topic(&t, json),
+                None => guide::render_guide_toc(json),
+            },
+        },
     }
 }

src/map.rs

@@ -0,0 +1,867 @@
+use colored::Colorize;
+use serde::Serialize;
+use std::collections::{HashMap, VecDeque};
+use std::path::{Path, PathBuf};
+
+use crate::ast_parser::{self, ProjectSymbols};
+use crate::complexity;
+use crate::deps;
+use crate::loc;
+use crate::render;
+
+/// Information about a module for the map view.
+struct ModuleBox {
+    name: String,
+    structs: Vec<String>,
+    enums: Vec<String>,
+    traits: Vec<String>,
+    functions: Vec<String>,
+    pub_count: usize,
+    total_count: usize,
+    code_lines: usize,
+    /// Per-function complexity scores (for heatbar).
+    func_scores: Vec<f64>,
+    /// Total connectivity (in-degree + out-degree).
+    connectivity: usize,
+}
+
+/// An inter-tier connection.
+struct TierEdge {
+    from_tier: usize,
+    to_tier: usize,
+    from_mod: String,
+    to_mod: String,
+}
+
+/// Print the tier header separator line.
+fn render_tier_header(tier_idx: usize, max_tier: usize, term_w: usize) {
+    let tier_label = match tier_idx {
+        0 => "Entry Points".to_string(),
+        t if t == max_tier && max_tier > 0 => "Leaf Modules".to_string(),
+        t => format!("Layer {}", t),
+    };
+    let separator = format!(
+        "╶╶╶ {} {}",
+        tier_label,
+        "╶".repeat(term_w.saturating_sub(tier_label.len()).saturating_sub(6))
+    );
+    println!("\n{}", separator.dimmed());
+}
+
+/// Render the module boxes for a single tier in a side-by-side layout.
+fn render_tier_modules(
+    group: &[String],
+    module_boxes: &HashMap<String, ModuleBox>,
+    hub_threshold: usize,
+    max_loc: usize,
+    term_w: usize,
+) {
+    let box_min_width = 30;
+    let max_side_by_side = (term_w / box_min_width).max(1);
+
+    let mut i = 0;
+    while i < group.len() {
+        let row_end = (i + max_side_by_side).min(group.len());
+        let row = &group[i..row_end];
+        let col_count = row.len();
+        let col_width = if col_count > 1 {
+            (term_w / col_count).min(term_w).max(box_min_width)
+        } else {
+            term_w.min(80).max(box_min_width)
+        };
+
+        let mut box_lines: Vec<Vec<String>> = Vec::new();
+        for mod_name in row {
+            if let Some(mbox) = module_boxes.get(mod_name.as_str()) {
+                let is_hub = mbox.connectivity >= hub_threshold && hub_threshold > 0;
+                let height = proportional_height(mbox.code_lines, max_loc);
+                let lines = render_module_box(mbox, col_width.saturating_sub(1), is_hub, height);
+                box_lines.push(lines);
+            }
+        }
+
+        let max_lines = box_lines.iter().map(|b| b.len()).max().unwrap_or(0);
+
+        for line_idx in 0..max_lines {
+            let mut row_str = String::new();
+            for (col_idx, lines) in box_lines.iter().enumerate() {
+                let line = if line_idx < lines.len() {
+                    &lines[line_idx]
+                } else {
+                    ""
+                };
+                let vis_len = render::visible_len(line);
+                let pad = col_width.saturating_sub(1).saturating_sub(vis_len);
+                row_str.push_str(line);
+                row_str.push_str(&" ".repeat(pad));
+                if col_idx < box_lines.len() - 1 {
+                    row_str.push(' ');
+                }
+            }
+            println!("{}", row_str);
+        }
+
+        i = row_end;
+    }
+}
+
+/// Render weighted dependency arrows from the given tier to deeper tiers.
+fn render_tier_arrows(tier_edges: &[TierEdge], tier_idx: usize) {
+    let arrows_from_tier: Vec<&TierEdge> = tier_edges
+        .iter()
+        .filter(|e| e.from_tier == tier_idx && e.to_tier > tier_idx)
+        .collect();
+
+    if arrows_from_tier.is_empty() {
+        return;
+    }
+
+    let mut arrow_groups: HashMap<(&str, &str), usize> = HashMap::new();
+    for e in &arrows_from_tier {
+        *arrow_groups
+            .entry((e.from_mod.as_str(), e.to_mod.as_str()))
+            .or_insert(0) += 1;
+    }
+    let mut arrow_list: Vec<((&str, &str), usize)> = arrow_groups.into_iter().collect();
+    arrow_list.sort_by(|a, b| b.1.cmp(&a.1).then(a.0 .0.cmp(b.0 .0)));
+
+    let show_count = arrow_list.len().min(6);
+    let mut arrow_strs: Vec<String> = Vec::new();
+    for ((from, to), count) in arrow_list.iter().take(show_count) {
+        let weight_str = if *count > 1 {
+            format!("({})", count)
+        } else {
+            String::new()
+        };
+        arrow_strs.push(format!(
+            "{}→{}{}",
+            from.bright_blue(),
+            to.bright_blue(),
+            weight_str.dimmed()
+        ));
+    }
+    if arrow_list.len() > show_count {
+        arrow_strs.push(
+            format!("+{} more", arrow_list.len() - show_count)
+                .dimmed()
+                .to_string(),
+        );
+    }
+    println!("    {} {}", "───▶".dimmed(), arrow_strs.join("  "));
+}
+
+/// Prepared data for rendering the module map.
+struct MapRenderData {
+    module_boxes: HashMap<String, ModuleBox>,
+    tier_groups: Vec<Vec<String>>,
+    tier_edges: Vec<TierEdge>,
+    max_loc: usize,
+    hub_threshold: usize,
+    max_tier: usize,
+}
+
+/// Gather and prepare all data needed to render the module map.
+fn prepare_map_data(
+    rs_files: &[PathBuf],
+    project_path: &Path,
+    symbols: &ProjectSymbols,
+    dep_analysis: &deps::DepAnalysis,
+) -> Option<MapRenderData> {
+    // Get LoC data per file
+    let (file_stats, _) = loc::analyze_files(rs_files);
+    let mut loc_by_mod: HashMap<String, usize> = HashMap::new();
+    for stat in &file_stats {
+        let mod_name = render::module_name_from_path(&stat.path, project_path);
+        loc_by_mod.insert(mod_name, stat.code_lines);
+    }
+
+    // Get complexity data
+    let func_complexities = complexity::compute_all(symbols, project_path);
+    let mut complexity_by_mod: HashMap<String, Vec<f64>> = HashMap::new();
+    for fc in &func_complexities {
+        let mod_name = file_to_module_name(&fc.file);
+        complexity_by_mod
+            .entry(mod_name)
+            .or_default()
+            .push(fc.composite_score);
+    }
+
+    // Build module boxes
+    let module_boxes = build_module_boxes(
+        symbols,
+        project_path,
+        &loc_by_mod,
+        &complexity_by_mod,
+        dep_analysis,
+    );
+
+    if module_boxes.is_empty() {
+        return None;
+    }
+
+    // Compute tier assignments via dependency depth (BFS from roots)
+    let tiers = compute_tiers(&module_boxes, dep_analysis);
+
+    // Group modules by tier
+    let max_tier = tiers.values().copied().max().unwrap_or(0);
+    let mut tier_groups: Vec<Vec<String>> = vec![Vec::new(); max_tier + 1];
+    for (name, &tier) in &tiers {
+        tier_groups[tier].push(name.clone());
+    }
+    // Sort modules within each tier by LoC descending
+    for group in &mut tier_groups {
+        group.sort_by(|a, b| {
+            let a_loc = module_boxes
+                .get(a.as_str())
+                .map(|m| m.code_lines)
+                .unwrap_or(0);
+            let b_loc = module_boxes
+                .get(b.as_str())
+                .map(|m| m.code_lines)
+                .unwrap_or(0);
+            b_loc.cmp(&a_loc).then(a.cmp(b))
+        });
+    }
+
+    // Collect inter-tier edges
+    let mut tier_edges: Vec<TierEdge> = Vec::new();
+    for edge in &dep_analysis.edges {
+        let from_tier = tiers.get(edge.from.as_str()).copied().unwrap_or(0);
+        let to_tier = tiers.get(edge.to.as_str()).copied().unwrap_or(0);
+        tier_edges.push(TierEdge {
+            from_tier,
+            to_tier,
+            from_mod: edge.from.clone(),
+            to_mod: edge.to.clone(),
+        });
+    }
+
+    // Find max LoC for proportional sizing
+    let max_loc = module_boxes
+        .values()
+        .map(|m| m.code_lines)
+        .max()
+        .unwrap_or(1)
+        .max(1);
+
+    // Compute connectivity threshold for hub detection
+    let connectivities: Vec<usize> = module_boxes.values().map(|m| m.connectivity).collect();
+    let mean_conn = if connectivities.is_empty() {
+        0.0
+    } else {
+        connectivities.iter().sum::<usize>() as f64 / connectivities.len() as f64
+    };
+    let hub_threshold = (mean_conn + 1.0) as usize;
+
+    Some(MapRenderData {
+        module_boxes,
+        tier_groups,
+        tier_edges,
+        max_loc,
+        hub_threshold,
+        max_tier,
+    })
+}
+
+/// Render the bird's eye module map.
+pub fn render_map(rs_files: &[PathBuf], project_path: &Path, verbose: bool) {
+    let term_w = render::terminal_width();
+    let symbols = ast_parser::parse_project(rs_files);
+    let dep_analysis = deps::analyze_deps(rs_files, project_path);
+
+    println!(
+        "\n{}",
+        "── Architectural Module Map ───────────────────────────"
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Bird's-eye module map arranged by dependency depth (BFS from roots).",
+            "Tier 0 = Entry Points (zero in-degree — nothing depends on them).",
+            "Deepest tier = Leaf Modules (only depended upon, never import others).",
+            "Inside each box: S = structs, E = enums, T = traits, f = functions.",
+            "  Numbers after the module name: LoC count and pub/total item ratio.",
+            "  ● (white) in the legend = public items (pub fn, pub struct, etc.).",
+            "Heatbar (▁▃▅▇) = per-function complexity distribution within the module:",
+            "  green (▁) = low complexity, yellow (▅) = medium, red (▇) = high.",
+            "Border style: ╔ (double-line, bold) = hub module (connectivity > mean+1σ).",
+            "  ┌ (single-line, dimmed) = regular or leaf module.",
+            "Arrows (───▶) show cross-tier dependency flow between modules.",
+            "  Arrow weight in parentheses = number of dependency edges along that path.",
+        ]);
+        render::guide_ref("architecture");
+    }
+
+    if symbols.files.is_empty() {
+        println!("  {}", "No modules found.".dimmed());
+        return;
+    }
+
+    let data = match prepare_map_data(rs_files, project_path, &symbols, &dep_analysis) {
+        Some(d) => d,
+        None => {
+            println!("  {}", "No modules found.".dimmed());
+            return;
+        }
+    };
+
+    // Render tier by tier (top = tier 0 = entry points, bottom = leaves)
+    for tier_idx in 0..=data.max_tier {
+        let group = &data.tier_groups[tier_idx];
+        if group.is_empty() {
+            continue;
+        }
+
+        render_tier_header(tier_idx, data.max_tier, term_w);
+        render_tier_modules(
+            group,
+            &data.module_boxes,
+            data.hub_threshold,
+            data.max_loc,
+            term_w,
+        );
+        render_tier_arrows(&data.tier_edges, tier_idx);
+    }
+
+    // Legend
+    println!();
+    println!(
+        "  {} struct  {} enum  {} trait  {} fn  {} pub  {} hub  {} leaf",
+        "S".bright_green().bold(),
+        "E".bright_yellow().bold(),
+        "T".bright_magenta().bold(),
+        "f".bright_blue(),
+        "●".white().bold(),
+        "╔".bold(),
+        "┌".dimmed(),
+    );
+    println!(
+        "  {} complexity heatbar: {} low {} med {} high",
+        "▁▃▅▇".dimmed(),
+        "▁".green(),
+        "▅".yellow(),
+        "▇".red(),
+    );
+    println!();
+}
+
+/// Convert a file path like "src/foo.rs" to module name "foo".
+fn file_to_module_name(file: &str) -> String {
+    let s = file.strip_suffix(".rs").unwrap_or(file);
+    let s = s.replace('/', "::");
+    let s = s.strip_prefix("src::").unwrap_or(&s);
+    if s.ends_with("::mod") {
+        s.strip_suffix("::mod").unwrap_or(s).to_string()
+    } else {
+        s.to_string()
+    }
+}
+
+/// Build module boxes with LoC, complexity, and connectivity data.
+fn build_module_boxes(
+    symbols: &ProjectSymbols,
+    project_path: &Path,
+    loc_by_mod: &HashMap<String, usize>,
+    complexity_by_mod: &HashMap<String, Vec<f64>>,
+    dep_analysis: &deps::DepAnalysis,
+) -> HashMap<String, ModuleBox> {
+    let mut boxes: HashMap<String, ModuleBox> = HashMap::new();
+
+    for file_syms in &symbols.files {
+        let mod_name = render::module_name_from_path(&file_syms.path, project_path);
+
+        let structs: Vec<String> = file_syms.structs.iter().map(|s| s.name.clone()).collect();
+        let enums: Vec<String> = file_syms.enums.iter().map(|e| e.name.clone()).collect();
+        let traits: Vec<String> = file_syms.traits.iter().map(|t| t.name.clone()).collect();
+        let functions: Vec<String> = file_syms
+            .functions
+            .iter()
+            .filter(|f| !f.name.contains("::"))
+            .map(|f| f.name.clone())
+            .collect();
+
+        let total = structs.len() + enums.len() + traits.len() + functions.len();
+        let pub_count = count_pub_items(&file_syms.path);
+        let code_lines = loc_by_mod.get(&mod_name).copied().unwrap_or(0);
+
+        let func_scores = complexity_by_mod
+            .get(&mod_name)
+            .cloned()
+            .unwrap_or_default();
+
+        let in_d = dep_analysis.in_degree.get(&mod_name).copied().unwrap_or(0);
+        let out_d = dep_analysis.out_degree.get(&mod_name).copied().unwrap_or(0);
+        let connectivity = in_d + out_d;
+
+        boxes.insert(
+            mod_name.clone(),
+            ModuleBox {
+                name: mod_name,
+                structs,
+                enums,
+                traits,
+                functions,
+                pub_count,
+                total_count: total,
+                code_lines,
+                func_scores,
+                connectivity,
+            },
+        );
+    }
+
+    boxes
+}
+
+/// Count `pub fn`, `pub struct`, `pub enum`, `pub trait` in source file.
+fn count_pub_items(path: &Path) -> usize {
+    let content = match std::fs::read_to_string(path) {
+        Ok(c) => c,
+        Err(_) => return 0,
+    };
+    let ast = match syn::parse_file(&content) {
+        Ok(f) => f,
+        Err(_) => return 0,
+    };
+    let mut count = 0;
+    for item in &ast.items {
+        match item {
+            syn::Item::Fn(f) => {
+                if matches!(f.vis, syn::Visibility::Public(_)) {
+                    count += 1;
+                }
+            }
+            syn::Item::Struct(s) => {
+                if matches!(s.vis, syn::Visibility::Public(_)) {
+                    count += 1;
+                }
+            }
+            syn::Item::Enum(e) => {
+                if matches!(e.vis, syn::Visibility::Public(_)) {
+                    count += 1;
+                }
+            }
+            syn::Item::Trait(t) => {
+                if matches!(t.vis, syn::Visibility::Public(_)) {
+                    count += 1;
+                }
+            }
+            _ => {}
+        }
+    }
+    count
+}
+
+/// Compute dependency depth tiers via BFS from root modules (zero in-degree).
+fn compute_tiers(
+    module_boxes: &HashMap<String, ModuleBox>,
+    dep_analysis: &deps::DepAnalysis,
+) -> HashMap<String, usize> {
+    let mut tiers: HashMap<String, usize> = HashMap::new();
+    let mut queue: VecDeque<String> = VecDeque::new();
+
+    // Build adjacency list: from -> [to] (follows dependency direction)
+    let mut adj: HashMap<&str, Vec<&str>> = HashMap::new();
+    for edge in &dep_analysis.edges {
+        adj.entry(edge.from.as_str())
+            .or_default()
+            .push(edge.to.as_str());
+    }
+
+    // Start from modules with zero in-degree (entry points / roots)
+    for name in module_boxes.keys() {
+        let in_d = dep_analysis.in_degree.get(name).copied().unwrap_or(0);
+        if in_d == 0 {
+            tiers.insert(name.clone(), 0);
+            queue.push_back(name.clone());
+        }
+    }
+
+    // If no roots found (all cycles), start everyone at tier 0
+    if queue.is_empty() {
+        for name in module_boxes.keys() {
+            tiers.insert(name.clone(), 0);
+        }
+        return tiers;
+    }
+
+    // BFS: propagate max depth. Limit iterations to avoid infinite loops on cycles.
+    let max_iterations = module_boxes.len() * module_boxes.len() + 1;
+    let mut iterations = 0;
+    while let Some(current) = queue.pop_front() {
+        iterations += 1;
+        if iterations > max_iterations {
+            break;
+        }
+        let current_tier = tiers[&current];
+        if let Some(neighbors) = adj.get(current.as_str()) {
+            for &neighbor in neighbors {
+                let new_tier = current_tier + 1;
+                let existing = tiers.get(neighbor).copied();
+                if existing.is_none() || new_tier > existing.unwrap() {
+                    // Cap tier depth to prevent runaway on cycles
+                    if new_tier <= module_boxes.len() {
+                        tiers.insert(neighbor.to_string(), new_tier);
+                        queue.push_back(neighbor.to_string());
+                    }
+                }
+            }
+        }
+    }
+
+    // Ensure all modules have a tier
+    for name in module_boxes.keys() {
+        tiers.entry(name.clone()).or_insert(0);
+    }
+
+    tiers
+}
+
+/// Compute proportional height (content lines) based on LoC.
+/// Minimum 1, maximum 6.
+fn proportional_height(code_lines: usize, max_loc: usize) -> usize {
+    if max_loc == 0 || code_lines == 0 {
+        return 1;
+    }
+    let ratio = code_lines as f64 / max_loc as f64;
+    let height = (ratio * 5.0).ceil() as usize + 1;
+    height.clamp(1, 6)
+}
+
+/// Build the header line for a module box.
+fn render_box_header(
+    mbox: &ModuleBox,
+    box_width: usize,
+    is_hub: bool,
+    h: &str,
+    tl: &str,
+    tr: &str,
+) -> String {
+    let header = format!(" {} ", mbox.name);
+    let pub_hint = format!("{}/{} pub", mbox.pub_count, mbox.total_count);
+    let loc_hint = format!("{} loc", mbox.code_lines);
+    let meta = format!("{} {}", loc_hint, pub_hint);
+    let fill_len = box_width
+        .saturating_sub(2)
+        .saturating_sub(header.len())
+        .saturating_sub(meta.len())
+        .saturating_sub(2);
+    let fill = h.repeat(fill_len);
+
+    if is_hub {
+        format!(
+            "{}{}{}{}{}{}",
+            tl.bold(),
+            h.repeat(1).bold(),
+            header.white().bold(),
+            fill.bold(),
+            format!(" {} ", meta).dimmed(),
+            tr.bold(),
+        )
+    } else {
+        format!(
+            "{}{}{}{}{}{}",
+            tl.dimmed(),
+            h.repeat(1).dimmed(),
+            header.white().bold(),
+            fill.dimmed(),
+            format!(" {} ", meta).dimmed(),
+            tr.dimmed(),
+        )
+    }
+}
+
+/// Build the content lines (heatbar, symbols) for a module box.
+fn build_box_content(mbox: &ModuleBox, inner_w: usize, prop_height: usize) -> Vec<String> {
+    let mut content: Vec<String> = Vec::new();
+
+    // Complexity heatbar
+    let heatbar = build_heatbar(&mbox.func_scores, inner_w);
+    if !heatbar.is_empty() {
+        content.push(heatbar);
+    }
+
+    // Structs
+    if !mbox.structs.is_empty() {
+        let items = abbreviate_list(&mbox.structs, inner_w.saturating_sub(2));
+        content.push(format!("{} {}", "S".bright_green().bold(), items));
+    }
+
+    // Enums
+    if !mbox.enums.is_empty() {
+        let items = abbreviate_list(&mbox.enums, inner_w.saturating_sub(2));
+        content.push(format!("{} {}", "E".bright_yellow().bold(), items));
+    }
+
+    // Traits
+    if !mbox.traits.is_empty() {
+        let items = abbreviate_list(&mbox.traits, inner_w.saturating_sub(2));
+        content.push(format!("{} {}", "T".bright_magenta().bold(), items));
+    }
+
+    // Functions
+    if !mbox.functions.is_empty() {
+        let items = abbreviate_list(&mbox.functions, inner_w.saturating_sub(2));
+        content.push(format!("{} {}", "f".bright_blue(), items));
+    }
+
+    if content.is_empty() {
+        content.push(format!("{}", "(empty)".dimmed()));
+    }
+
+    // Pad or trim to proportional height
+    while content.len() < prop_height {
+        content.push(String::new());
+    }
+    if content.len() > prop_height && prop_height > 0 {
+        content.truncate(prop_height);
+    }
+
+    content
+}
+
+/// Render bordered content lines and the footer of a module box.
+fn render_box_body(
+    content: &[String],
+    inner_w: usize,
+    box_width: usize,
+    is_hub: bool,
+    v: &str,
+    bl: &str,
+    br: &str,
+    h: &str,
+) -> Vec<String> {
+    let mut lines = Vec::new();
+
+    for line in content {
+        let vis_len = render::visible_len(line);
+        let pad = inner_w.saturating_sub(vis_len);
+        if is_hub {
+            lines.push(format!(
+                "{} {}{} {}",
+                v.bold(),
+                line,
+                " ".repeat(pad),
+                v.bold()
+            ));
+        } else {
+            lines.push(format!(
+                "{} {}{} {}",
+                v.dimmed(),
+                line,
+                " ".repeat(pad),
+                v.dimmed()
+            ));
+        }
+    }
+
+    // Footer
+    let footer_fill = box_width.saturating_sub(2);
+    if is_hub {
+        lines.push(format!(
+            "{}{}{}",
+            bl.bold(),
+            h.repeat(footer_fill).bold(),
+            br.bold()
+        ));
+    } else {
+        lines.push(format!(
+            "{}{}{}",
+            bl.dimmed(),
+            h.repeat(footer_fill).dimmed(),
+            br.dimmed()
+        ));
+    }
+
+    lines
+}
+
+/// Render a single module box, returning lines.
+fn render_module_box(
+    mbox: &ModuleBox,
+    box_width: usize,
+    is_hub: bool,
+    prop_height: usize,
+) -> Vec<String> {
+    let box_width = box_width.max(20);
+    let inner_w = box_width.saturating_sub(4); // "│ " + " │" = 4 chars
+
+    // Border characters: hubs get bold double-line borders
+    let (tl, tr, bl, br, h, v) = if is_hub {
+        ("╔", "╗", "╚", "╝", "═", "║")
+    } else {
+        ("┌", "┐", "└", "┘", "─", "│")
+    };
+
+    let mut lines = Vec::new();
+    lines.push(render_box_header(mbox, box_width, is_hub, h, tl, tr));
+    let content = build_box_content(mbox, inner_w, prop_height);
+    lines.extend(render_box_body(
+        &content, inner_w, box_width, is_hub, v, bl, br, h,
+    ));
+    lines
+}
+
+/// Build a complexity heatbar from function scores.
+fn build_heatbar(scores: &[f64], max_width: usize) -> String {
+    if scores.is_empty() {
+        return String::new();
+    }
+
+    let blocks = ['▁', '▂', '▃', '▄', '▅', '▆', '▇', '█'];
+    let max_score = scores.iter().cloned().fold(0.0f64, f64::max).max(1.0);
+
+    let bar_width = max_width.min(scores.len());
+    let mut result = String::new();
+
+    if scores.len() <= bar_width {
+        let mut sorted_scores = scores.to_vec();
+        sorted_scores.sort_by(|a, b| a.partial_cmp(b).unwrap_or(std::cmp::Ordering::Equal));
+        for &score in &sorted_scores {
+            let ratio = score / max_score;
+            let idx = (ratio * (blocks.len() - 1) as f64).round() as usize;
+            let idx = idx.min(blocks.len() - 1);
+            let ch = blocks[idx].to_string();
+            let colored = if ratio < 0.33 {
+                ch.green().to_string()
+            } else if ratio < 0.66 {
+                ch.yellow().to_string()
+            } else {
+                ch.red().to_string()
+            };
+            result.push_str(&colored);
+        }
+    } else {
+        let bucket_size = (scores.len() as f64 / bar_width as f64).ceil() as usize;
+        let mut sorted_scores = scores.to_vec();
+        sorted_scores.sort_by(|a, b| a.partial_cmp(b).unwrap_or(std::cmp::Ordering::Equal));
+        for chunk in sorted_scores.chunks(bucket_size) {
+            let bucket_max = chunk.iter().cloned().fold(0.0f64, f64::max);
+            let ratio = bucket_max / max_score;
+            let idx = (ratio * (blocks.len() - 1) as f64).round() as usize;
+            let idx = idx.min(blocks.len() - 1);
+            let ch = blocks[idx].to_string();
+            let colored = if ratio < 0.33 {
+                ch.green().to_string()
+            } else if ratio < 0.66 {
+                ch.yellow().to_string()
+            } else {
+                ch.red().to_string()
+            };
+            result.push_str(&colored);
+        }
+    }
+
+    result
+}
+
+/// Abbreviate a list of names to fit within the given width.
+fn abbreviate_list(names: &[String], max_width: usize) -> String {
+    let mut result = String::new();
+    let mut remaining = names.len();
+
+    for (i, name) in names.iter().enumerate() {
+        let separator = if i > 0 { ", " } else { "" };
+        let addition = format!("{}{}", separator, name);
+
+        if result.len() + addition.len() > max_width && i > 0 {
+            let more = remaining;
+            result.push_str(&format!(" +{}", more));
+            break;
+        }
+
+        result.push_str(&addition);
+        remaining -= 1;
+    }
+
+    result
+}
+
+#[derive(Serialize)]
+struct ModuleMetadataJson {
+    name: String,
+    structs: Vec<String>,
+    enums: Vec<String>,
+    traits: Vec<String>,
+    functions: Vec<String>,
+    pub_count: usize,
+    total_count: usize,
+    code_lines: usize,
+    tier: usize,
+    is_hub: bool,
+    complexity_scores: Vec<f64>,
+}
+
+#[derive(Serialize)]
+struct MapJson {
+    cstat_version: String,
+    modules: Vec<ModuleMetadataJson>,
+}
+
+/// Render module map as JSON.
+pub fn render_map_json(rs_files: &[PathBuf], project_path: &Path) {
+    let symbols = ast_parser::parse_project(rs_files);
+    let dep_analysis = deps::analyze_deps(rs_files, project_path);
+
+    let (file_stats, _) = loc::analyze_files(rs_files);
+    let mut loc_by_mod: HashMap<String, usize> = HashMap::new();
+    for stat in &file_stats {
+        let mod_name = render::module_name_from_path(&stat.path, project_path);
+        loc_by_mod.insert(mod_name, stat.code_lines);
+    }
+
+    let func_complexities = complexity::compute_all(&symbols, project_path);
+    let mut complexity_by_mod: HashMap<String, Vec<f64>> = HashMap::new();
+    for fc in &func_complexities {
+        let mod_name = file_to_module_name(&fc.file);
+        complexity_by_mod
+            .entry(mod_name)
+            .or_default()
+            .push(fc.composite_score);
+    }
+
+    let module_boxes = build_module_boxes(
+        &symbols,
+        project_path,
+        &loc_by_mod,
+        &complexity_by_mod,
+        &dep_analysis,
+    );
+
+    let tiers = compute_tiers(&module_boxes, &dep_analysis);
+
+    let connectivities: Vec<usize> = module_boxes.values().map(|m| m.connectivity).collect();
+    let mean_conn = if connectivities.is_empty() {
+        0.0
+    } else {
+        connectivities.iter().sum::<usize>() as f64 / connectivities.len() as f64
+    };
+    let hub_threshold = (mean_conn + 1.0) as usize;
+
+    let mut modules: Vec<ModuleMetadataJson> = module_boxes
+        .values()
+        .map(|mbox| ModuleMetadataJson {
+            name: mbox.name.clone(),
+            structs: mbox.structs.clone(),
+            enums: mbox.enums.clone(),
+            traits: mbox.traits.clone(),
+            functions: mbox.functions.clone(),
+            pub_count: mbox.pub_count,
+            total_count: mbox.total_count,
+            code_lines: mbox.code_lines,
+            tier: tiers.get(&mbox.name).copied().unwrap_or(0),
+            is_hub: mbox.connectivity >= hub_threshold && hub_threshold > 0,
+            complexity_scores: mbox.func_scores.clone(),
+        })
+        .collect();
+    modules.sort_by(|a, b| a.tier.cmp(&b.tier).then(b.code_lines.cmp(&a.code_lines)));
+
+    let output = MapJson {
+        cstat_version: env!("CARGO_PKG_VERSION").to_string(),
+        modules,
+    };
+
+    println!("{}", serde_json::to_string(&output).unwrap());
+}

src/redundancy.rs

@@ -0,0 +1,673 @@
+use colored::Colorize;
+use serde::Serialize;
+use std::collections::hash_map::DefaultHasher;
+use std::collections::{HashMap, HashSet};
+use std::hash::{Hash, Hasher};
+use std::path::{Path, PathBuf};
+use syn::visit::Visit;
+use syn::{Expr, File as SynFile, ImplItem, Item, ReturnType, Type};
+
+use crate::render;
+
+/// Information about a function sufficient for redundancy comparison.
+#[derive(Debug, Clone)]
+struct FunctionSig {
+    name: String,
+    file: String,
+    line_start: usize,
+    param_types: Vec<String>,
+    return_type: String,
+}
+
+/// A pair of functions flagged as potentially redundant.
+#[derive(Debug, Clone)]
+pub struct RedundantPair {
+    pub func_a: String,
+    pub file_a: String,
+    pub line_a: usize,
+    pub func_b: String,
+    pub file_b: String,
+    pub line_b: usize,
+    pub similarity: f64,
+    pub kind: SimilarityKind,
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub enum SimilarityKind {
+    Signature,
+    Structural,
+    Both,
+}
+
+impl std::fmt::Display for SimilarityKind {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            SimilarityKind::Signature => write!(f, "signature"),
+            SimilarityKind::Structural => write!(f, "structural"),
+            SimilarityKind::Both => write!(f, "both"),
+        }
+    }
+}
+
+// ── Signature extraction ─────────────────────────────────────────────
+
+/// Extract function signatures from all project files.
+fn extract_signatures(rs_files: &[PathBuf], project_path: &Path) -> Vec<FunctionSig> {
+    let mut sigs = Vec::new();
+
+    for file in rs_files {
+        let content = match std::fs::read_to_string(file) {
+            Ok(c) => c,
+            Err(_) => continue,
+        };
+
+        let ast: SynFile = match syn::parse_file(&content) {
+            Ok(f) => f,
+            Err(_) => continue,
+        };
+
+        let rel_path = file
+            .strip_prefix(project_path)
+            .unwrap_or(file)
+            .display()
+            .to_string();
+
+        for item in &ast.items {
+            match item {
+                Item::Fn(func) => {
+                    let sig = extract_fn_sig(&func.sig, &func.sig.ident.to_string(), &rel_path);
+                    sigs.push(sig);
+                }
+                Item::Impl(imp) => {
+                    let type_name = type_to_short(&imp.self_ty);
+                    for impl_item in &imp.items {
+                        if let ImplItem::Fn(method) = impl_item {
+                            let qualified = format!("{}::{}", type_name, method.sig.ident);
+                            let sig = extract_fn_sig(&method.sig, &qualified, &rel_path);
+                            sigs.push(sig);
+                        }
+                    }
+                }
+                _ => {}
+            }
+        }
+    }
+
+    sigs
+}
+
+fn extract_fn_sig(sig: &syn::Signature, name: &str, file: &str) -> FunctionSig {
+    let param_types: Vec<String> = sig
+        .inputs
+        .iter()
+        .filter_map(|arg| match arg {
+            syn::FnArg::Typed(pat_type) => Some(type_to_short(&pat_type.ty)),
+            syn::FnArg::Receiver(_) => Some("self".to_string()),
+        })
+        .collect();
+
+    let return_type = match &sig.output {
+        ReturnType::Default => "()".to_string(),
+        ReturnType::Type(_, ty) => type_to_short(ty),
+    };
+
+    let line_start = sig.fn_token.span.start().line;
+
+    FunctionSig {
+        name: name.to_string(),
+        file: file.to_string(),
+        line_start,
+        param_types,
+        return_type,
+    }
+}
+
+fn type_to_short(ty: &Type) -> String {
+    match ty {
+        Type::Path(tp) => tp
+            .path
+            .segments
+            .iter()
+            .map(|s| {
+                let ident = s.ident.to_string();
+                if let syn::PathArguments::AngleBracketed(args) = &s.arguments {
+                    let inner: Vec<String> = args
+                        .args
+                        .iter()
+                        .filter_map(|a| {
+                            if let syn::GenericArgument::Type(t) = a {
+                                Some(type_to_short(t))
+                            } else {
+                                None
+                            }
+                        })
+                        .collect();
+                    if inner.is_empty() {
+                        ident
+                    } else {
+                        format!("{}<{}>", ident, inner.join(", "))
+                    }
+                } else {
+                    ident
+                }
+            })
+            .collect::<Vec<_>>()
+            .join("::"),
+        Type::Reference(r) => {
+            let mutability = if r.mutability.is_some() { "&mut " } else { "&" };
+            format!("{}{}", mutability, type_to_short(&r.elem))
+        }
+        Type::Tuple(t) => {
+            let inner: Vec<String> = t.elems.iter().map(type_to_short).collect();
+            format!("({})", inner.join(", "))
+        }
+        Type::Slice(s) => format!("[{}]", type_to_short(&s.elem)),
+        Type::Array(a) => format!("[{}; _]", type_to_short(&a.elem)),
+        Type::ImplTrait(_) => "impl Trait".to_string(),
+        Type::TraitObject(_) => "dyn Trait".to_string(),
+        _ => "?".to_string(),
+    }
+}
+
+// ── Pass 1: Signature similarity ─────────────────────────────────────
+
+/// Compute normalized Levenshtein distance between two strings (0.0 = identical, 1.0 = completely different).
+fn levenshtein_distance(a: &str, b: &str) -> f64 {
+    let a_chars: Vec<char> = a.chars().collect();
+    let b_chars: Vec<char> = b.chars().collect();
+    let m = a_chars.len();
+    let n = b_chars.len();
+
+    if m == 0 && n == 0 {
+        return 0.0;
+    }
+    if m == 0 || n == 0 {
+        return 1.0;
+    }
+
+    let mut prev = vec![0usize; n + 1];
+    let mut curr = vec![0usize; n + 1];
+
+    for j in 0..=n {
+        prev[j] = j;
+    }
+
+    for i in 1..=m {
+        curr[0] = i;
+        for j in 1..=n {
+            let cost = if a_chars[i - 1] == b_chars[j - 1] {
+                0
+            } else {
+                1
+            };
+            curr[j] = (prev[j] + 1).min(curr[j - 1] + 1).min(prev[j - 1] + cost);
+        }
+        std::mem::swap(&mut prev, &mut curr);
+    }
+
+    let max_len = m.max(n);
+    prev[n] as f64 / max_len as f64
+}
+
+/// Name similarity: 1.0 - normalized_levenshtein. Also checks substring containment.
+fn name_similarity(a: &str, b: &str) -> f64 {
+    // Use the "bare" name (after last ::) for comparison
+    let a_bare = a.rsplit("::").next().unwrap_or(a);
+    let b_bare = b.rsplit("::").next().unwrap_or(b);
+
+    let lev_sim = 1.0 - levenshtein_distance(a_bare, b_bare);
+
+    // Substring containment bonus
+    let substr_sim = if a_bare.len() >= 3 && b_bare.len() >= 3 {
+        if a_bare.contains(b_bare) || b_bare.contains(a_bare) {
+            let shorter = a_bare.len().min(b_bare.len()) as f64;
+            let longer = a_bare.len().max(b_bare.len()) as f64;
+            shorter / longer
+        } else {
+            0.0
+        }
+    } else {
+        0.0
+    };
+
+    lev_sim.max(substr_sim)
+}
+
+/// Jaccard index on parameter type sets.
+fn param_type_jaccard(a: &[String], b: &[String]) -> f64 {
+    if a.is_empty() && b.is_empty() {
+        return 1.0;
+    }
+    if a.is_empty() || b.is_empty() {
+        return 0.0;
+    }
+
+    let set_a: HashSet<&str> = a.iter().map(|s| s.as_str()).collect();
+    let set_b: HashSet<&str> = b.iter().map(|s| s.as_str()).collect();
+
+    let intersection = set_a.intersection(&set_b).count() as f64;
+    let union = set_a.union(&set_b).count() as f64;
+
+    if union == 0.0 {
+        0.0
+    } else {
+        intersection / union
+    }
+}
+
+/// Compute signature similarity between two functions. Returns 0.0..1.0.
+fn signature_similarity(a: &FunctionSig, b: &FunctionSig) -> f64 {
+    let name_sim = name_similarity(&a.name, &b.name);
+    let param_sim = param_type_jaccard(&a.param_types, &b.param_types);
+    let ret_sim = if a.return_type == b.return_type {
+        1.0
+    } else {
+        0.0
+    };
+
+    // Weighted combination
+    0.4 * name_sim + 0.4 * param_sim + 0.2 * ret_sim
+}
+
+/// Find signature-similar pairs above a threshold.
+fn find_signature_pairs(sigs: &[FunctionSig], threshold: f64) -> Vec<(usize, usize, f64)> {
+    let mut pairs = Vec::new();
+
+    for i in 0..sigs.len() {
+        for j in (i + 1)..sigs.len() {
+            // Skip trivially tiny functions (getters, etc.)
+            if sigs[i].param_types.is_empty()
+                && sigs[j].param_types.is_empty()
+                && sigs[i].return_type == "()"
+                && sigs[j].return_type == "()"
+            {
+                continue;
+            }
+
+            let sim = signature_similarity(&sigs[i], &sigs[j]);
+            if sim >= threshold {
+                pairs.push((i, j, sim));
+            }
+        }
+    }
+
+    pairs
+}
+
+// ── Pass 2: Structural similarity ────────────────────────────────────
+
+/// Normalized AST node kind (stripping identifiers and literals).
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
+enum NormNode {
+    Block(usize), // number of statements
+    If,
+    Match(usize), // number of arms
+    For,
+    While,
+    Loop,
+    Let,
+    Return,
+    Call(usize), // number of arguments
+    MethodCall(usize),
+    Binary,
+    Unary,
+    Closure(usize), // number of params
+    Index,
+    Field,
+    Assign,
+    Break,
+    Continue,
+    Literal,
+    Path,
+    Other,
+}
+
+/// Extract a structural hash from a function body by normalizing the AST.
+fn structural_hash_from_file(
+    file_path: &Path,
+    _project_path: &Path,
+    func_name: &str,
+) -> Option<u64> {
+    let content = std::fs::read_to_string(file_path).ok()?;
+    let ast = syn::parse_file(&content).ok()?;
+
+    for item in &ast.items {
+        match item {
+            Item::Fn(func) => {
+                if func.sig.ident == func_name || func_name == func.sig.ident.to_string() {
+                    return Some(hash_block(&func.block));
+                }
+            }
+            Item::Impl(imp) => {
+                let type_name = type_to_short(&imp.self_ty);
+                for impl_item in &imp.items {
+                    if let ImplItem::Fn(method) = impl_item {
+                        let qualified = format!("{}::{}", type_name, method.sig.ident);
+                        if qualified == func_name {
+                            return Some(hash_block(&method.block));
+                        }
+                    }
+                }
+            }
+            _ => {}
+        }
+    }
+
+    None
+}
+
+/// Hash a block by normalizing its structure.
+fn hash_block(block: &syn::Block) -> u64 {
+    let mut nodes = Vec::new();
+    let mut visitor = StructuralVisitor { nodes: &mut nodes };
+    visitor.visit_block(block);
+
+    let mut hasher = DefaultHasher::new();
+    nodes.hash(&mut hasher);
+    hasher.finish()
+}
+
+struct StructuralVisitor<'a> {
+    nodes: &'a mut Vec<NormNode>,
+}
+
+impl<'a, 'ast> Visit<'ast> for StructuralVisitor<'a> {
+    fn visit_block(&mut self, block: &'ast syn::Block) {
+        self.nodes.push(NormNode::Block(block.stmts.len()));
+        syn::visit::visit_block(self, block);
+    }
+
+    fn visit_expr(&mut self, expr: &'ast Expr) {
+        match expr {
+            Expr::If(_) => self.nodes.push(NormNode::If),
+            Expr::Match(m) => self.nodes.push(NormNode::Match(m.arms.len())),
+            Expr::ForLoop(_) => self.nodes.push(NormNode::For),
+            Expr::While(_) => self.nodes.push(NormNode::While),
+            Expr::Loop(_) => self.nodes.push(NormNode::Loop),
+            Expr::Return(_) => self.nodes.push(NormNode::Return),
+            Expr::Call(c) => self.nodes.push(NormNode::Call(c.args.len())),
+            Expr::MethodCall(m) => self.nodes.push(NormNode::MethodCall(m.args.len())),
+            Expr::Binary(_) => self.nodes.push(NormNode::Binary),
+            Expr::Unary(_) => self.nodes.push(NormNode::Unary),
+            Expr::Closure(c) => self.nodes.push(NormNode::Closure(c.inputs.len())),
+            Expr::Index(_) => self.nodes.push(NormNode::Index),
+            Expr::Field(_) => self.nodes.push(NormNode::Field),
+            Expr::Assign(_) => self.nodes.push(NormNode::Assign),
+            Expr::Break(_) => self.nodes.push(NormNode::Break),
+            Expr::Continue(_) => self.nodes.push(NormNode::Continue),
+            Expr::Lit(_) => self.nodes.push(NormNode::Literal),
+            Expr::Path(_) => self.nodes.push(NormNode::Path),
+            _ => self.nodes.push(NormNode::Other),
+        }
+        syn::visit::visit_expr(self, expr);
+    }
+
+    fn visit_local(&mut self, _local: &'ast syn::Local) {
+        self.nodes.push(NormNode::Let);
+        syn::visit::visit_local(self, _local);
+    }
+}
+
+// ── Analysis entry point ─────────────────────────────────────────────
+
+const SIG_THRESHOLD: f64 = 0.6;
+const REPORT_THRESHOLD: f64 = 0.7;
+
+/// Find structural duplicate pairs from functions sharing identical AST hashes.
+fn find_structural_duplicates(
+    sigs: &[FunctionSig],
+    structural_hashes: &HashMap<usize, u64>,
+) -> (Vec<RedundantPair>, HashSet<(usize, usize)>) {
+    let mut hash_to_indices: HashMap<u64, Vec<usize>> = HashMap::new();
+    for (&idx, &hash) in structural_hashes {
+        hash_to_indices.entry(hash).or_default().push(idx);
+    }
+
+    let mut results: Vec<RedundantPair> = Vec::new();
+    let mut seen_pairs: HashSet<(usize, usize)> = HashSet::new();
+
+    for indices in hash_to_indices.values() {
+        if indices.len() < 2 {
+            continue;
+        }
+        for i in 0..indices.len() {
+            for j in (i + 1)..indices.len() {
+                let a = indices[i].min(indices[j]);
+                let b = indices[i].max(indices[j]);
+                if seen_pairs.insert((a, b)) {
+                    let sig_sim = signature_similarity(&sigs[a], &sigs[b]);
+                    let kind = if sig_sim >= SIG_THRESHOLD {
+                        SimilarityKind::Both
+                    } else {
+                        SimilarityKind::Structural
+                    };
+                    results.push(RedundantPair {
+                        func_a: sigs[a].name.clone(),
+                        file_a: sigs[a].file.clone(),
+                        line_a: sigs[a].line_start,
+                        func_b: sigs[b].name.clone(),
+                        file_b: sigs[b].file.clone(),
+                        line_b: sigs[b].line_start,
+                        similarity: 1.0,
+                        kind,
+                    });
+                }
+            }
+        }
+    }
+
+    (results, seen_pairs)
+}
+
+/// Merge signature-similar pairs that were not already found as structural duplicates.
+fn merge_signature_pairs(
+    sig_pairs: &[(usize, usize, f64)],
+    sigs: &[FunctionSig],
+    structural_hashes: &HashMap<usize, u64>,
+    seen_pairs: &mut HashSet<(usize, usize)>,
+) -> Vec<RedundantPair> {
+    let mut results = Vec::new();
+
+    for (i, j, sim) in sig_pairs {
+        let a = (*i).min(*j);
+        let b = (*i).max(*j);
+        if seen_pairs.contains(&(a, b)) || *sim < REPORT_THRESHOLD {
+            continue;
+        }
+
+        let struct_match = match (structural_hashes.get(&a), structural_hashes.get(&b)) {
+            (Some(ha), Some(hb)) => ha == hb,
+            _ => false,
+        };
+
+        let (final_sim, kind) = if struct_match {
+            (1.0, SimilarityKind::Both)
+        } else {
+            (*sim, SimilarityKind::Signature)
+        };
+
+        seen_pairs.insert((a, b));
+        results.push(RedundantPair {
+            func_a: sigs[a].name.clone(),
+            file_a: sigs[a].file.clone(),
+            line_a: sigs[a].line_start,
+            func_b: sigs[b].name.clone(),
+            file_b: sigs[b].file.clone(),
+            line_b: sigs[b].line_start,
+            similarity: final_sim,
+            kind,
+        });
+    }
+
+    results
+}
+
+/// Run redundancy detection on the project. Returns pairs sorted by similarity descending.
+pub fn detect_redundancy(rs_files: &[PathBuf], project_path: &Path) -> Vec<RedundantPair> {
+    let sigs = extract_signatures(rs_files, project_path);
+
+    if sigs.len() < 2 {
+        return Vec::new();
+    }
+
+    // Pass 1: signature similarity
+    let sig_pairs = find_signature_pairs(&sigs, SIG_THRESHOLD);
+
+    // Pass 2: structural hashes for all functions
+    let mut structural_hashes: HashMap<usize, u64> = HashMap::new();
+    for (i, sig) in sigs.iter().enumerate() {
+        let full_path = project_path.join(&sig.file);
+        if let Some(hash) = structural_hash_from_file(&full_path, project_path, &sig.name) {
+            structural_hashes.insert(i, hash);
+        }
+    }
+
+    // Find structural duplicates
+    let (mut results, mut seen_pairs) = find_structural_duplicates(&sigs, &structural_hashes);
+
+    // Merge in signature-similar pairs
+    let sig_results = merge_signature_pairs(&sig_pairs, &sigs, &structural_hashes, &mut seen_pairs);
+    results.extend(sig_results);
+
+    // Sort by similarity descending
+    results.sort_by(|a, b| {
+        b.similarity
+            .partial_cmp(&a.similarity)
+            .unwrap_or(std::cmp::Ordering::Equal)
+    });
+
+    results
+}
+
+// ── Human-readable rendering ─────────────────────────────────────────
+
+pub fn render_redundancy(rs_files: &[PathBuf], project_path: &Path, verbose: bool) {
+    let pairs = detect_redundancy(rs_files, project_path);
+
+    println!(
+        "\n{}",
+        "── Redundancy Detection ──────────────────────────────────"
+            .bright_cyan()
+            .bold()
+    );
+
+    if verbose {
+        render::verbose_block(&[
+            "Detects suspected duplicate or near-duplicate functions.",
+            "Pass 1: Signature similarity — compares function names, parameter types, and return types.",
+            "Pass 2: Structural similarity — normalizes ASTs (strips identifiers/literals) and compares hashes.",
+            "Similarity 1.00 = structurally identical. >= 0.70 = signature-similar candidates.",
+            "Kind: 'signature' = similar signatures, 'structural' = identical AST structure, 'both' = both match.",
+        ]);
+        render::guide_ref("redundancy");
+    }
+
+    if pairs.is_empty() {
+        println!("\n  {}", "No suspected duplicates found.".green());
+        println!();
+        return;
+    }
+
+    println!(
+        "\n  {} suspected duplicate pair(s) found:\n",
+        format!("{}", pairs.len()).bold()
+    );
+
+    // Header
+    println!(
+        "  {:<35} {:<35} {:>5} {}",
+        "Function A".bold().underline(),
+        "Function B".bold().underline(),
+        "Sim".bold().underline(),
+        "Kind".bold().underline(),
+    );
+
+    for pair in &pairs {
+        let name_a = if pair.func_a.len() > 33 {
+            format!("{}...", &pair.func_a[..30])
+        } else {
+            pair.func_a.clone()
+        };
+        let name_b = if pair.func_b.len() > 33 {
+            format!("{}...", &pair.func_b[..30])
+        } else {
+            pair.func_b.clone()
+        };
+
+        let sim_str = format!("{:.2}", pair.similarity);
+        let colored_sim = if pair.similarity >= 0.9 {
+            sim_str.red().bold().to_string()
+        } else {
+            sim_str.yellow().to_string()
+        };
+
+        let kind_str = match pair.kind {
+            SimilarityKind::Both => "both".red().to_string(),
+            SimilarityKind::Structural => "structural".yellow().to_string(),
+            SimilarityKind::Signature => "signature".dimmed().to_string(),
+        };
+
+        println!(
+            "  {:<35} {:<35} {:>5} {}",
+            name_a.dimmed(),
+            name_b.dimmed(),
+            colored_sim,
+            kind_str,
+        );
+        println!(
+            "  {:<35} {}",
+            format!("  {}:{}", pair.file_a, pair.line_a).dimmed(),
+            format!("  {}:{}", pair.file_b, pair.line_b).dimmed(),
+        );
+    }
+
+    println!();
+}
+
+// ── JSON rendering ───────────────────────────────────────────────────
+
+#[derive(Serialize)]
+struct RedundantPairJson {
+    func_a: String,
+    file_a: String,
+    line_a: usize,
+    func_b: String,
+    file_b: String,
+    line_b: usize,
+    similarity: f64,
+    kind: String,
+}
+
+#[derive(Serialize)]
+struct RedundancyJson {
+    cstat_version: String,
+    redundant_pairs: Vec<RedundantPairJson>,
+    total_pairs: usize,
+}
+
+pub fn render_redundancy_json(rs_files: &[PathBuf], project_path: &Path) {
+    let pairs = detect_redundancy(rs_files, project_path);
+
+    let total = pairs.len();
+    let json_pairs: Vec<RedundantPairJson> = pairs
+        .into_iter()
+        .map(|p| RedundantPairJson {
+            func_a: p.func_a,
+            file_a: p.file_a,
+            line_a: p.line_a,
+            func_b: p.func_b,
+            file_b: p.file_b,
+            line_b: p.line_b,
+            similarity: p.similarity,
+            kind: p.kind.to_string(),
+        })
+        .collect();
+
+    let output = RedundancyJson {
+        cstat_version: env!("CARGO_PKG_VERSION").to_string(),
+        redundant_pairs: json_pairs,
+        total_pairs: total,
+    };
+
+    println!("{}", serde_json::to_string(&output).unwrap());
+}

src/report.rs

@@ -0,0 +1,298 @@
+use colored::Colorize;
+use serde::Serialize;
+use std::collections::HashMap;
+use std::path::{Path, PathBuf};
+
+use crate::{ast_parser, datapaths, dead_code, deps, flow, loc, render, symbols};
+
+#[derive(Debug, Clone, Serialize)]
+pub struct LineCountFile {
+    pub path: String,
+    pub total_lines: usize,
+    pub code_lines: usize,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct LineCountReport {
+    pub total_files: usize,
+    pub total_lines: usize,
+    pub total_code_lines: usize,
+    pub mean_code_lines: f64,
+    pub median_code_lines: usize,
+    pub files: Vec<LineCountFile>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ModuleDegree {
+    pub module: String,
+    pub fan_in: usize,
+    pub fan_out: usize,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct ModuleDependencyMatrix {
+    pub modules: Vec<String>,
+    pub matrix: Vec<Vec<usize>>,
+    pub edges: usize,
+    pub degrees: Vec<ModuleDegree>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+pub struct FocusReport {
+    pub cstat_version: String,
+    pub project: String,
+    pub line_counts: LineCountReport,
+    pub symbols: symbols::SymbolReport,
+    pub dependencies: ModuleDependencyMatrix,
+    pub dead_code: dead_code::DeadCodeReport,
+    pub test_reachability: datapaths::TestReachabilityAnalysis,
+}
+
+pub fn build_report(rs_files: &[PathBuf], project_path: &Path) -> FocusReport {
+    let project_path = project_path
+        .canonicalize()
+        .unwrap_or_else(|_| project_path.to_path_buf());
+    let project = project_path
+        .file_name()
+        .map(|name| name.to_string_lossy().to_string())
+        .unwrap_or_else(|| "unknown".to_string());
+
+    let (file_stats, aggregate) = loc::analyze_files(rs_files);
+    let symbols_raw = ast_parser::parse_project(rs_files);
+    let dep_analysis = deps::analyze_deps(rs_files, &project_path);
+    let call_graph = flow::build_call_graph(rs_files, &project_path);
+
+    FocusReport {
+        cstat_version: env!("CARGO_PKG_VERSION").to_string(),
+        project,
+        line_counts: build_line_report(&file_stats, aggregate.as_ref(), &project_path),
+        symbols: symbols::analyze_symbols(&symbols_raw, &project_path),
+        dependencies: build_dependency_matrix(&dep_analysis),
+        dead_code: dead_code::analyze_graph(&call_graph),
+        test_reachability: datapaths::analyze_graph_test_reachability(&call_graph),
+    }
+}
+
+pub fn render_report(rs_files: &[PathBuf], project_path: &Path, verbose: bool) {
+    let report = build_report(rs_files, project_path);
+    render_report_data(&report, verbose);
+}
+
+pub fn render_report_json(rs_files: &[PathBuf], project_path: &Path) {
+    let report = build_report(rs_files, project_path);
+    println!("{}", serde_json::to_string(&report).unwrap());
+}
+
+pub fn render_report_data(report: &FocusReport, verbose: bool) {
+    println!(
+        "\n{} {}",
+        "cstat focused report".bright_cyan().bold(),
+        format!("({})", report.project).dimmed()
+    );
+    println!(
+        "{}",
+        "Objective module metrics: size, symbols, dependencies, dead-code candidates, and test/bench reachability."
+            .dimmed()
+    );
+
+    render_line_counts(&report.line_counts, verbose);
+    symbols::render_symbol_report(&report.symbols, verbose);
+    render_dependency_matrix(&report.dependencies, verbose);
+    dead_code::render_dead_code_report(&report.dead_code, verbose);
+    datapaths::render_test_reachability_report(&report.test_reachability, verbose);
+}
+
+fn build_line_report(
+    file_stats: &[loc::FileLocStats],
+    aggregate: Option<&loc::AggregateStats>,
+    project_path: &Path,
+) -> LineCountReport {
+    let total_lines = file_stats.iter().map(|file| file.total_lines).sum();
+    let files: Vec<LineCountFile> = file_stats
+        .iter()
+        .map(|file| LineCountFile {
+            path: file
+                .path
+                .strip_prefix(project_path)
+                .unwrap_or(&file.path)
+                .display()
+                .to_string(),
+            total_lines: file.total_lines,
+            code_lines: file.code_lines,
+        })
+        .collect();
+
+    LineCountReport {
+        total_files: aggregate.map_or(file_stats.len(), |agg| agg.total_files),
+        total_lines,
+        total_code_lines: aggregate.map_or(0, |agg| agg.total_loc),
+        mean_code_lines: aggregate.map_or(0.0, |agg| agg.mean),
+        median_code_lines: aggregate.map_or(0, |agg| agg.median),
+        files,
+    }
+}
+
+fn build_dependency_matrix(dep_analysis: &deps::DepAnalysis) -> ModuleDependencyMatrix {
+    let modules = dep_analysis.modules.clone();
+    let module_index: HashMap<&str, usize> = modules
+        .iter()
+        .enumerate()
+        .map(|(idx, module)| (module.as_str(), idx))
+        .collect();
+    let mut matrix = vec![vec![0usize; modules.len()]; modules.len()];
+
+    for edge in &dep_analysis.edges {
+        if let (Some(from), Some(to)) = (
+            module_index.get(edge.from.as_str()),
+            module_index.get(edge.to.as_str()),
+        ) {
+            matrix[*from][*to] = 1;
+        }
+    }
+
+    let mut degrees: Vec<ModuleDegree> = modules
+        .iter()
+        .map(|module| ModuleDegree {
+            module: module.clone(),
+            fan_in: dep_analysis.in_degree.get(module).copied().unwrap_or(0),
+            fan_out: dep_analysis.out_degree.get(module).copied().unwrap_or(0),
+        })
+        .collect();
+    degrees.sort_by(|a, b| {
+        (b.fan_in + b.fan_out)
+            .cmp(&(a.fan_in + a.fan_out))
+            .then(a.module.cmp(&b.module))
+    });
+
+    ModuleDependencyMatrix {
+        modules,
+        matrix,
+        edges: dep_analysis.edges.len(),
+        degrees,
+    }
+}
+
+fn render_line_counts(report: &LineCountReport, verbose: bool) {
+    render::section_header("Line counts");
+
+    if verbose {
+        render::verbose_block(&[
+            "Code lines exclude blank lines and comment-only lines.",
+            "Physical lines are kept beside code lines so generated or dense files are visible.",
+        ]);
+    }
+
+    println!(
+        "  {} {}  {} {}  {} {:.1}  {} {}",
+        "files".cyan(),
+        report.total_files.to_string().bold(),
+        "code lines".cyan(),
+        report.total_code_lines.to_string().bold(),
+        "mean".cyan(),
+        report.mean_code_lines,
+        "median".cyan(),
+        report.median_code_lines.to_string().bold(),
+    );
+
+    println!();
+    println!(
+        "  {:<56} {:>8} {:>8}",
+        "file".bold(),
+        "code".bold(),
+        "physical".bold()
+    );
+    for file in &report.files {
+        println!(
+            "  {:<56} {:>8} {:>8}",
+            truncate(&file.path, 56),
+            file.code_lines,
+            file.total_lines,
+        );
+    }
+}
+
+fn render_dependency_matrix(report: &ModuleDependencyMatrix, verbose: bool) {
+    render::section_header("Module dependency matrix");
+
+    if verbose {
+        render::verbose_block(&[
+            "Rows are modules that depend on columns.",
+            "A 1 means at least one source-level use/mod edge from row to column.",
+            "The index list keeps the matrix readable for medium-sized crates.",
+        ]);
+    }
+
+    println!(
+        "  {} {}  {} {}",
+        "modules".cyan(),
+        report.modules.len().to_string().bold(),
+        "edges".cyan(),
+        report.edges.to_string().bold(),
+    );
+
+    if report.modules.is_empty() {
+        println!("  {}", "No modules found.".yellow());
+        return;
+    }
+
+    println!();
+    for (idx, module) in report.modules.iter().enumerate() {
+        println!("  [{:>2}] {}", idx, module);
+    }
+
+    let cell_width = report
+        .modules
+        .len()
+        .saturating_sub(1)
+        .to_string()
+        .len()
+        .max(1);
+    println!();
+    print!("  {:>3} │", "");
+    for idx in 0..report.modules.len() {
+        print!(" {:>width$}", idx, width = cell_width);
+    }
+    println!();
+    print!("  {}─┼", "─".repeat(3));
+    for _ in 0..report.modules.len() {
+        print!("{}", "─".repeat(cell_width + 1));
+    }
+    println!();
+
+    for (idx, row) in report.matrix.iter().enumerate() {
+        print!("  {:>3} │", idx);
+        for value in row {
+            print!(" {:>width$}", value, width = cell_width);
+        }
+        println!();
+    }
+
+    let connected: Vec<&ModuleDegree> = report
+        .degrees
+        .iter()
+        .filter(|degree| degree.fan_in + degree.fan_out > 0)
+        .take(10)
+        .collect();
+    if !connected.is_empty() {
+        println!();
+        println!("  {}", "Highest fan-in/fan-out:".bold());
+        for degree in connected {
+            println!(
+                "  {:<40} in {:>3}  out {:>3}",
+                truncate(&degree.module, 40),
+                degree.fan_in,
+                degree.fan_out,
+            );
+        }
+    }
+}
+
+fn truncate(value: &str, max: usize) -> String {
+    if value.chars().count() <= max {
+        value.to_string()
+    } else {
+        let mut out: String = value.chars().take(max.saturating_sub(1)).collect();
+        out.push('…');
+        out
+    }
+}

src/scorecard.rs

@@ -1,980 +0,0 @@
-use colored::Colorize;
-use serde::Serialize;
-use serde_json::json;
-use std::collections::{BTreeMap, HashMap};
-use std::path::{Path, PathBuf};
-
-use crate::{ast_parser, dead_code, deps, flow, loc, render};
-
-const SCORE_VERSION: &str = "code_complexity_cost_v0";
-const DEFAULT_TOP: usize = 20;
-
-#[derive(Debug, Clone, Serialize)]
-pub struct ScorecardReport {
-    pub cstat_version: String,
-    pub score_version: String,
-    pub target: String,
-    pub code_complexity_cost: f64,
-    pub code_complexity_cost_per_kloc: f64,
-    pub component_costs: ComponentCosts,
-    pub scope_breakdown: BTreeMap<String, ScopeSummary>,
-    pub top_contributors: Vec<TopContributor>,
-    pub metadata: ScoreMetadata,
-}
-
-#[derive(Debug, Clone, Serialize)]
-pub struct ComponentCosts {
-    pub function_complexity: FunctionComponent,
-    pub file_concentration: FileComponent,
-    pub module_coupling: ModuleComponent,
-    pub abstraction_surface: AbstractionComponent,
-    pub stale_surface: StaleComponent,
-}
-
-#[derive(Debug, Clone, Serialize)]
-pub struct FunctionComponent {
-    pub cost: f64,
-    pub functions_scored: usize,
-}
-
-#[derive(Debug, Clone, Serialize)]
-pub struct FileComponent {
-    pub cost: f64,
-    pub files_scored: usize,
-}
-
-#[derive(Debug, Clone, Serialize)]
-pub struct ModuleComponent {
-    pub cost: f64,
-    pub modules_scored: usize,
-}
-
-#[derive(Debug, Clone, Serialize)]
-pub struct AbstractionComponent {
-    pub cost: f64,
-    pub symbols_scored: usize,
-}
-
-#[derive(Debug, Clone, Serialize)]
-pub struct StaleComponent {
-    pub cost: f64,
-    pub candidate_count: usize,
-}
-
-#[derive(Debug, Clone, Default, Serialize)]
-pub struct ScopeSummary {
-    pub cost: f64,
-    pub functions_scored: usize,
-    pub files_scored: usize,
-}
-
-#[derive(Debug, Clone, Serialize)]
-pub struct TopContributor {
-    pub kind: String,
-    pub scope: String,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub file: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub module: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub function: Option<String>,
-    pub cost: f64,
-    pub reasons: BTreeMap<String, serde_json::Value>,
-    pub component_costs: BTreeMap<String, f64>,
-}
-
-#[derive(Debug, Clone, Serialize)]
-pub struct ScoreMetadata {
-    pub rust_files: usize,
-    pub code_lines: usize,
-    pub parse_error_files: usize,
-}
-
-#[derive(Debug, Clone, Default)]
-struct ScopeAccumulator {
-    cost: f64,
-    functions_scored: usize,
-    files_scored: usize,
-}
-
-#[derive(Debug, Clone)]
-struct Contributor {
-    kind: String,
-    scope: String,
-    file: Option<String>,
-    module: Option<String>,
-    function: Option<String>,
-    cost: f64,
-    reasons: BTreeMap<String, serde_json::Value>,
-    component_costs: BTreeMap<String, f64>,
-}
-
-#[derive(Debug, Clone)]
-struct FunctionScoreInput {
-    file: String,
-    function: String,
-    graph_name: String,
-    scope: String,
-    cyclomatic: usize,
-    nesting_depth: usize,
-    line_count: usize,
-    body_stmt_count: usize,
-    signature_score: usize,
-}
-
-pub fn render_scorecard(
-    files: &[PathBuf],
-    project_path: &Path,
-    target: &str,
-    top: Option<usize>,
-    json_output: bool,
-    verbose: bool,
-) {
-    let report = analyze_scorecard(files, project_path, target, top.unwrap_or(DEFAULT_TOP));
-    if json_output {
-        println!("{}", serde_json::to_string(&report).unwrap());
-    } else {
-        render_scorecard_human(&report, verbose);
-    }
-}
-
-pub fn analyze_scorecard(
-    files: &[PathBuf],
-    project_path: &Path,
-    target: &str,
-    top: usize,
-) -> ScorecardReport {
-    let symbols = ast_parser::parse_project(files);
-    let graph = flow::build_call_graph(files, project_path);
-    let loc_by_file = collect_loc_by_file(files);
-    let file_scopes = collect_file_scopes(files, project_path);
-    let function_inputs = collect_function_inputs(&symbols, &graph, project_path, &file_scopes);
-
-    let mut scope_totals = initial_scope_totals(files, &symbols, project_path, &file_scopes);
-    let mut contributors = Vec::new();
-
-    let function_complexity =
-        score_functions(&function_inputs, &mut scope_totals, &mut contributors);
-    let file_concentration = score_files(
-        &symbols,
-        &loc_by_file,
-        project_path,
-        &file_scopes,
-        &mut scope_totals,
-        &mut contributors,
-    );
-    let abstraction_surface = score_abstraction_surface(
-        &symbols,
-        project_path,
-        &file_scopes,
-        &mut scope_totals,
-        &mut contributors,
-    );
-    let module_coupling = score_module_coupling(
-        files,
-        project_path,
-        &file_scopes,
-        &mut scope_totals,
-        &mut contributors,
-    );
-    let stale_surface = score_stale_surface(
-        &graph,
-        &function_inputs,
-        &mut scope_totals,
-        &mut contributors,
-    );
-
-    contributors.sort_by(|a, b| {
-        b.cost
-            .partial_cmp(&a.cost)
-            .unwrap_or(std::cmp::Ordering::Equal)
-            .then_with(|| a.kind.cmp(&b.kind))
-            .then_with(|| a.file.cmp(&b.file))
-            .then_with(|| a.module.cmp(&b.module))
-            .then_with(|| a.function.cmp(&b.function))
-    });
-    contributors.truncate(top);
-
-    let code_lines: usize = loc_by_file.values().map(|stats| stats.code_lines).sum();
-    let total_cost = function_complexity.cost
-        + file_concentration.cost
-        + module_coupling.cost
-        + abstraction_surface.cost
-        + stale_surface.cost;
-    let kloc = (code_lines as f64 / 1000.0).max(1.0);
-
-    ScorecardReport {
-        cstat_version: env!("CARGO_PKG_VERSION").to_string(),
-        score_version: SCORE_VERSION.to_string(),
-        target: target.to_string(),
-        code_complexity_cost: round1(total_cost),
-        code_complexity_cost_per_kloc: round1(total_cost / kloc),
-        component_costs: ComponentCosts {
-            function_complexity: FunctionComponent {
-                cost: round1(function_complexity.cost),
-                functions_scored: function_complexity.functions_scored,
-            },
-            file_concentration: FileComponent {
-                cost: round1(file_concentration.cost),
-                files_scored: file_concentration.files_scored,
-            },
-            module_coupling: ModuleComponent {
-                cost: round1(module_coupling.cost),
-                modules_scored: module_coupling.modules_scored,
-            },
-            abstraction_surface: AbstractionComponent {
-                cost: round1(abstraction_surface.cost),
-                symbols_scored: abstraction_surface.symbols_scored,
-            },
-            stale_surface: StaleComponent {
-                cost: round1(stale_surface.cost),
-                candidate_count: stale_surface.candidate_count,
-            },
-        },
-        scope_breakdown: finalize_scope_totals(scope_totals),
-        top_contributors: contributors
-            .into_iter()
-            .map(|contributor| TopContributor {
-                kind: contributor.kind,
-                scope: contributor.scope,
-                file: contributor.file,
-                module: contributor.module,
-                function: contributor.function,
-                cost: round1(contributor.cost),
-                reasons: contributor.reasons,
-                component_costs: contributor
-                    .component_costs
-                    .into_iter()
-                    .map(|(key, value)| (key, round1(value)))
-                    .collect(),
-            })
-            .collect(),
-        metadata: ScoreMetadata {
-            rust_files: files.len(),
-            code_lines,
-            parse_error_files: symbols.files.iter().filter(|file| file.parse_error).count(),
-        },
-    }
-}
-
-fn render_scorecard_human(report: &ScorecardReport, verbose: bool) {
-    render::section_header("Code complexity score");
-    println!("score version: {}", report.score_version.bold());
-    println!("lower is cleaner; harness guards behavior separately");
-    if verbose {
-        render::verbose_block(&[
-            "Pure structural cost; no tests, benchmark, coverage, reward, or behavior signals are included.",
-            "All discovered Rust scopes contribute equally; scope breakdown is explanatory only.",
-            "This command is a compact scorecard, not a bundle of every underlying probe.",
-        ]);
-    } else {
-        println!();
-    }
-
-    println!("total cost: {:.1}", report.code_complexity_cost);
-    println!("cost / KLOC: {:.1}", report.code_complexity_cost_per_kloc);
-    println!();
-    println!("components:");
-    println!(
-        "  {:<24} {:>8.1}",
-        "function complexity:", report.component_costs.function_complexity.cost
-    );
-    println!(
-        "  {:<24} {:>8.1}",
-        "file concentration:", report.component_costs.file_concentration.cost
-    );
-    println!(
-        "  {:<24} {:>8.1}",
-        "module coupling:", report.component_costs.module_coupling.cost
-    );
-    println!(
-        "  {:<24} {:>8.1}",
-        "abstraction surface:", report.component_costs.abstraction_surface.cost
-    );
-    println!(
-        "  {:<24} {:>8.1}",
-        "stale surface:", report.component_costs.stale_surface.cost
-    );
-
-    println!();
-    println!("top contributors:");
-    if report.top_contributors.is_empty() {
-        println!("  <none>");
-    } else {
-        for (index, contributor) in report.top_contributors.iter().enumerate() {
-            println!(
-                "  {:>2}. {:<19} {:<48} {:>8.1}",
-                index + 1,
-                contributor.kind,
-                contributor_label(contributor),
-                contributor.cost,
-            );
-        }
-    }
-}
-
-fn contributor_label(contributor: &TopContributor) -> String {
-    match contributor.kind.as_str() {
-        "function" => match (&contributor.file, &contributor.function) {
-            (Some(file), Some(function)) => format!("{file}::{function}"),
-            _ => contributor
-                .function
-                .clone()
-                .unwrap_or_else(|| "<unknown>".to_string()),
-        },
-        "file" | "abstraction_surface" => contributor
-            .file
-            .clone()
-            .unwrap_or_else(|| "<unknown>".to_string()),
-        "module" => contributor
-            .module
-            .clone()
-            .unwrap_or_else(|| "<unknown>".to_string()),
-        "stale_surface" => contributor
-            .function
-            .clone()
-            .unwrap_or_else(|| "<unknown>".to_string()),
-        _ => "<unknown>".to_string(),
-    }
-}
-
-#[derive(Default)]
-struct FunctionScoreSummary {
-    cost: f64,
-    functions_scored: usize,
-}
-
-#[derive(Default)]
-struct FileScoreSummary {
-    cost: f64,
-    files_scored: usize,
-}
-
-#[derive(Default)]
-struct ModuleScoreSummary {
-    cost: f64,
-    modules_scored: usize,
-}
-
-#[derive(Default)]
-struct AbstractionScoreSummary {
-    cost: f64,
-    symbols_scored: usize,
-}
-
-#[derive(Default)]
-struct StaleScoreSummary {
-    cost: f64,
-    candidate_count: usize,
-}
-
-fn score_functions(
-    functions: &[FunctionScoreInput],
-    scopes: &mut BTreeMap<String, ScopeAccumulator>,
-    contributors: &mut Vec<Contributor>,
-) -> FunctionScoreSummary {
-    let mut summary = FunctionScoreSummary {
-        functions_scored: functions.len(),
-        ..Default::default()
-    };
-
-    for function in functions {
-        let branch_cost = 2.0 * excess(function.cyclomatic, 5);
-        let nesting_cost = 3.0 * excess(function.nesting_depth, 3);
-        let span_cost = 0.2 * excess(function.line_count, 50);
-        let body_cost = 0.5 * excess(function.body_stmt_count, 20);
-        let signature_cost = excess(function.signature_score, 6);
-        let cost = branch_cost + nesting_cost + span_cost + body_cost + signature_cost;
-
-        summary.cost += cost;
-        add_scope_cost(scopes, &function.scope, cost);
-
-        if cost > 0.0 {
-            let mut reasons = BTreeMap::new();
-            reasons.insert("cyclomatic".to_string(), json!(function.cyclomatic));
-            reasons.insert("nesting_depth".to_string(), json!(function.nesting_depth));
-            reasons.insert("line_count".to_string(), json!(function.line_count));
-            reasons.insert(
-                "body_stmt_count".to_string(),
-                json!(function.body_stmt_count),
-            );
-            reasons.insert(
-                "signature_score".to_string(),
-                json!(function.signature_score),
-            );
-
-            let mut component_costs = BTreeMap::new();
-            component_costs.insert("branching".to_string(), branch_cost);
-            component_costs.insert("nesting".to_string(), nesting_cost);
-            component_costs.insert("span".to_string(), span_cost);
-            component_costs.insert("body_statements".to_string(), body_cost);
-            component_costs.insert("signature".to_string(), signature_cost);
-
-            contributors.push(Contributor {
-                kind: "function".to_string(),
-                scope: function.scope.clone(),
-                file: Some(function.file.clone()),
-                module: None,
-                function: Some(function.function.clone()),
-                cost,
-                reasons,
-                component_costs,
-            });
-        }
-    }
-
-    summary
-}
-
-fn score_files(
-    symbols: &ast_parser::ProjectSymbols,
-    loc_by_file: &HashMap<PathBuf, loc::FileLocStats>,
-    project_path: &Path,
-    file_scopes: &HashMap<PathBuf, String>,
-    scopes: &mut BTreeMap<String, ScopeAccumulator>,
-    contributors: &mut Vec<Contributor>,
-) -> FileScoreSummary {
-    let mut summary = FileScoreSummary {
-        files_scored: symbols.files.len(),
-        ..Default::default()
-    };
-
-    for file in &symbols.files {
-        let code_lines = loc_by_file
-            .get(&file.path)
-            .map(|stats| stats.code_lines)
-            .unwrap_or_default();
-        let total_symbols = total_symbols(file);
-        let function_count = file.functions.len();
-        let line_cost = 0.04 * excess(code_lines, 400);
-        let symbol_cost = 0.25 * excess(total_symbols, 35);
-        let function_count_cost = excess(function_count, 25);
-        let cost = line_cost + symbol_cost + function_count_cost;
-        let scope = file_scopes
-            .get(&file.path)
-            .cloned()
-            .unwrap_or_else(|| file_scope(&file.path, project_path));
-
-        summary.cost += cost;
-        add_scope_cost(scopes, &scope, cost);
-
-        if cost > 0.0 {
-            let mut reasons = BTreeMap::new();
-            reasons.insert("code_lines".to_string(), json!(code_lines));
-            reasons.insert("total_symbols".to_string(), json!(total_symbols));
-            reasons.insert("function_count".to_string(), json!(function_count));
-
-            let mut component_costs = BTreeMap::new();
-            component_costs.insert("code_lines".to_string(), line_cost);
-            component_costs.insert("symbols".to_string(), symbol_cost);
-            component_costs.insert("functions".to_string(), function_count_cost);
-
-            contributors.push(Contributor {
-                kind: "file".to_string(),
-                scope,
-                file: Some(relative_file(&file.path, project_path)),
-                module: None,
-                function: None,
-                cost,
-                reasons,
-                component_costs,
-            });
-        }
-    }
-
-    summary
-}
-
-fn score_abstraction_surface(
-    symbols: &ast_parser::ProjectSymbols,
-    project_path: &Path,
-    file_scopes: &HashMap<PathBuf, String>,
-    scopes: &mut BTreeMap<String, ScopeAccumulator>,
-    contributors: &mut Vec<Contributor>,
-) -> AbstractionScoreSummary {
-    let mut summary = AbstractionScoreSummary::default();
-
-    for file in &symbols.files {
-        let structs = file.structs.len();
-        let enums = file.enums.len();
-        let traits = file.traits.len();
-        let trait_impls = file
-            .impls
-            .iter()
-            .filter(|imp| imp.trait_name.is_some())
-            .count();
-        let consts_statics = file.consts.len() + file.statics.len();
-        summary.symbols_scored += total_symbols(file);
-
-        let struct_cost = 0.5 * excess(structs, 12);
-        let enum_cost = 0.5 * excess(enums, 8);
-        let trait_cost = excess(traits, 4);
-        let trait_impl_cost = 0.5 * excess(trait_impls, 8);
-        let const_static_cost = 0.2 * excess(consts_statics, 10);
-        let cost = struct_cost + enum_cost + trait_cost + trait_impl_cost + const_static_cost;
-        let scope = file_scopes
-            .get(&file.path)
-            .cloned()
-            .unwrap_or_else(|| file_scope(&file.path, project_path));
-
-        summary.cost += cost;
-        add_scope_cost(scopes, &scope, cost);
-
-        if cost > 0.0 {
-            let mut reasons = BTreeMap::new();
-            reasons.insert("structs".to_string(), json!(structs));
-            reasons.insert("enums".to_string(), json!(enums));
-            reasons.insert("traits".to_string(), json!(traits));
-            reasons.insert("trait_impls".to_string(), json!(trait_impls));
-            reasons.insert("consts_and_statics".to_string(), json!(consts_statics));
-
-            let mut component_costs = BTreeMap::new();
-            component_costs.insert("structs".to_string(), struct_cost);
-            component_costs.insert("enums".to_string(), enum_cost);
-            component_costs.insert("traits".to_string(), trait_cost);
-            component_costs.insert("trait_impls".to_string(), trait_impl_cost);
-            component_costs.insert("consts_and_statics".to_string(), const_static_cost);
-
-            contributors.push(Contributor {
-                kind: "abstraction_surface".to_string(),
-                scope,
-                file: Some(relative_file(&file.path, project_path)),
-                module: None,
-                function: None,
-                cost,
-                reasons,
-                component_costs,
-            });
-        }
-    }
-
-    summary
-}
-
-fn score_module_coupling(
-    files: &[PathBuf],
-    project_path: &Path,
-    file_scopes: &HashMap<PathBuf, String>,
-    scopes: &mut BTreeMap<String, ScopeAccumulator>,
-    contributors: &mut Vec<Contributor>,
-) -> ModuleScoreSummary {
-    let analysis = deps::analyze_deps(files, project_path);
-    let cohesion = deps::compute_cohesion(files, project_path);
-    let module_scopes = module_scopes(files, project_path, file_scopes);
-    let mut summary = ModuleScoreSummary {
-        modules_scored: analysis.modules.len(),
-        ..Default::default()
-    };
-
-    for module in &analysis.modules {
-        let in_degree = analysis.in_degree.get(module).copied().unwrap_or(0);
-        let out_degree = analysis.out_degree.get(module).copied().unwrap_or(0);
-        let out_cost = 2.0 * excess(out_degree, 5);
-        let in_cost = excess(in_degree, 10);
-        let cost = out_cost + in_cost;
-        let scope = module_scopes
-            .get(module)
-            .cloned()
-            .unwrap_or_else(|| "production".to_string());
-
-        summary.cost += cost;
-        add_scope_cost(scopes, &scope, cost);
-
-        if cost > 0.0 {
-            let mut reasons = BTreeMap::new();
-            reasons.insert("in_degree".to_string(), json!(in_degree));
-            reasons.insert("out_degree".to_string(), json!(out_degree));
-
-            let mut component_costs = BTreeMap::new();
-            component_costs.insert("fan_out".to_string(), out_cost);
-            component_costs.insert("fan_in".to_string(), in_cost);
-
-            contributors.push(Contributor {
-                kind: "module".to_string(),
-                scope,
-                file: None,
-                module: Some(module.clone()),
-                function: None,
-                cost,
-                reasons,
-                component_costs,
-            });
-        }
-    }
-
-    for (module_a, module_b, strength) in &analysis.coupling_pairs {
-        if *strength < 2 {
-            continue;
-        }
-        let cost = 20.0 + 5.0 * *strength as f64;
-        let scope = pair_scope(module_a, module_b, &module_scopes);
-        summary.cost += cost;
-        add_scope_cost(scopes, &scope, cost);
-
-        let mut reasons = BTreeMap::new();
-        reasons.insert("strength".to_string(), json!(strength));
-        reasons.insert("direction".to_string(), json!("bidirectional"));
-
-        let mut component_costs = BTreeMap::new();
-        component_costs.insert("bidirectional_pair".to_string(), cost);
-
-        contributors.push(Contributor {
-            kind: "module".to_string(),
-            scope,
-            file: None,
-            module: Some(format!("{module_a} <-> {module_b}")),
-            function: None,
-            cost,
-            reasons,
-            component_costs,
-        });
-    }
-
-    for row in &cohesion {
-        if row.function_count < 4 {
-            continue;
-        }
-        let cohesion_gap = (0.55 - row.combined).max(0.0);
-        let cost = 2.0 * row.function_count as f64 * cohesion_gap;
-        let scope = module_scopes
-            .get(&row.module)
-            .cloned()
-            .unwrap_or_else(|| "production".to_string());
-        summary.cost += cost;
-        add_scope_cost(scopes, &scope, cost);
-
-        if cost > 0.0 {
-            let mut reasons = BTreeMap::new();
-            reasons.insert("combined_cohesion".to_string(), json!(row.combined));
-            reasons.insert("function_count".to_string(), json!(row.function_count));
-
-            let mut component_costs = BTreeMap::new();
-            component_costs.insert("low_cohesion".to_string(), cost);
-
-            contributors.push(Contributor {
-                kind: "module".to_string(),
-                scope,
-                file: None,
-                module: Some(row.module.clone()),
-                function: None,
-                cost,
-                reasons,
-                component_costs,
-            });
-        }
-    }
-
-    summary
-}
-
-fn score_stale_surface(
-    graph: &flow::CallGraph,
-    functions: &[FunctionScoreInput],
-    scopes: &mut BTreeMap<String, ScopeAccumulator>,
-    contributors: &mut Vec<Contributor>,
-) -> StaleScoreSummary {
-    let report = dead_code::analyze_graph(graph);
-    let function_scopes: HashMap<&str, &str> = functions
-        .iter()
-        .map(|function| (function.graph_name.as_str(), function.scope.as_str()))
-        .collect();
-    let function_files: HashMap<&str, &str> = functions
-        .iter()
-        .map(|function| (function.graph_name.as_str(), function.file.as_str()))
-        .collect();
-    let summary = StaleScoreSummary {
-        candidate_count: report.candidate_count,
-        cost: 0.5 * report.candidate_count as f64,
-    };
-
-    for candidate in &report.candidates {
-        let cost = 0.5;
-        let scope = function_scopes
-            .get(candidate.function.as_str())
-            .map(|scope| (*scope).to_string())
-            .unwrap_or_else(|| graph_function_scope(graph, &candidate.function));
-        add_scope_cost(scopes, &scope, cost);
-
-        let mut reasons = BTreeMap::new();
-        reasons.insert("reason".to_string(), json!(candidate.reason));
-
-        let mut component_costs = BTreeMap::new();
-        component_costs.insert("stale_candidate".to_string(), cost);
-
-        contributors.push(Contributor {
-            kind: "stale_surface".to_string(),
-            scope,
-            file: function_files
-                .get(candidate.function.as_str())
-                .map(|file| (*file).to_string()),
-            module: None,
-            function: Some(candidate.function.clone()),
-            cost,
-            reasons,
-            component_costs,
-        });
-    }
-
-    summary
-}
-
-fn collect_function_inputs(
-    symbols: &ast_parser::ProjectSymbols,
-    graph: &flow::CallGraph,
-    project_path: &Path,
-    file_scopes: &HashMap<PathBuf, String>,
-) -> Vec<FunctionScoreInput> {
-    let mut inputs = Vec::new();
-
-    for file in &symbols.files {
-        let file_module = render::module_name_from_path(&file.path, project_path);
-        let rel_file = relative_file(&file.path, project_path);
-        let base_scope = file_scopes
-            .get(&file.path)
-            .cloned()
-            .unwrap_or_else(|| file_scope(&file.path, project_path));
-
-        for function in &file.functions {
-            let graph_name = graph_name_for_function(&file_module, &function.name);
-            let scope = function_scope(graph, &graph_name, &base_scope, function.is_test_support);
-            let line_count = function_line_count(function);
-            let signature_score = signature_score(function);
-            inputs.push(FunctionScoreInput {
-                file: rel_file.clone(),
-                function: function.name.clone(),
-                graph_name,
-                scope,
-                cyclomatic: function.branch_points + 1,
-                nesting_depth: function.nesting_depth,
-                line_count,
-                body_stmt_count: function.body_stmt_count,
-                signature_score,
-            });
-        }
-    }
-
-    inputs
-}
-
-fn collect_loc_by_file(files: &[PathBuf]) -> HashMap<PathBuf, loc::FileLocStats> {
-    files
-        .iter()
-        .filter_map(|file| loc::count_file_lines(file).map(|stats| (file.clone(), stats)))
-        .collect()
-}
-
-fn collect_file_scopes(files: &[PathBuf], project_path: &Path) -> HashMap<PathBuf, String> {
-    files
-        .iter()
-        .map(|file| (file.clone(), file_scope(file, project_path)))
-        .collect()
-}
-
-fn initial_scope_totals(
-    files: &[PathBuf],
-    symbols: &ast_parser::ProjectSymbols,
-    project_path: &Path,
-    file_scopes: &HashMap<PathBuf, String>,
-) -> BTreeMap<String, ScopeAccumulator> {
-    let mut scopes = BTreeMap::new();
-    for standard in ["production", "tests", "benches"] {
-        scopes.insert(standard.to_string(), ScopeAccumulator::default());
-    }
-
-    for file in files {
-        let scope = file_scopes
-            .get(file)
-            .cloned()
-            .unwrap_or_else(|| file_scope(file, project_path));
-        scopes.entry(scope).or_default().files_scored += 1;
-    }
-
-    for file in &symbols.files {
-        let scope = file_scopes
-            .get(&file.path)
-            .cloned()
-            .unwrap_or_else(|| file_scope(&file.path, project_path));
-        scopes.entry(scope).or_default().functions_scored += file.functions.len();
-    }
-
-    scopes
-}
-
-fn finalize_scope_totals(
-    scopes: BTreeMap<String, ScopeAccumulator>,
-) -> BTreeMap<String, ScopeSummary> {
-    scopes
-        .into_iter()
-        .map(|(scope, summary)| {
-            (
-                scope,
-                ScopeSummary {
-                    cost: round1(summary.cost),
-                    functions_scored: summary.functions_scored,
-                    files_scored: summary.files_scored,
-                },
-            )
-        })
-        .collect()
-}
-
-fn add_scope_cost(scopes: &mut BTreeMap<String, ScopeAccumulator>, scope: &str, cost: f64) {
-    scopes.entry(scope.to_string()).or_default().cost += cost;
-}
-
-fn module_scopes(
-    files: &[PathBuf],
-    project_path: &Path,
-    file_scopes: &HashMap<PathBuf, String>,
-) -> HashMap<String, String> {
-    files
-        .iter()
-        .map(|file| {
-            let module = render::module_name_from_path(file, project_path);
-            let scope = file_scopes
-                .get(file)
-                .cloned()
-                .unwrap_or_else(|| file_scope(file, project_path));
-            (module, scope)
-        })
-        .collect()
-}
-
-fn pair_scope(module_a: &str, module_b: &str, module_scopes: &HashMap<String, String>) -> String {
-    let scope_a = module_scopes
-        .get(module_a)
-        .cloned()
-        .unwrap_or_else(|| "production".to_string());
-    let scope_b = module_scopes
-        .get(module_b)
-        .cloned()
-        .unwrap_or_else(|| "production".to_string());
-    if scope_a == scope_b {
-        scope_a
-    } else {
-        "mixed".to_string()
-    }
-}
-
-fn function_scope(
-    graph: &flow::CallGraph,
-    graph_name: &str,
-    file_scope: &str,
-    is_test_support: bool,
-) -> String {
-    if file_scope == "benches" || file_scope == "tests" {
-        return file_scope.to_string();
-    }
-    if matches!(
-        graph.entry_point_kinds.get(graph_name),
-        Some(flow::EntryPointKind::Bench)
-    ) {
-        return "benches".to_string();
-    }
-    if matches!(
-        graph.entry_point_kinds.get(graph_name),
-        Some(flow::EntryPointKind::Test)
-    ) {
-        return "tests".to_string();
-    }
-    if let Some(node) = graph.function_nodes.get(graph_name) {
-        if node.is_bench_entry {
-            return "benches".to_string();
-        }
-        if node.is_test_entry || node.is_test_support {
-            return "tests".to_string();
-        }
-    }
-    if is_test_support {
-        return "tests".to_string();
-    }
-    file_scope.to_string()
-}
-
-fn graph_function_scope(graph: &flow::CallGraph, graph_name: &str) -> String {
-    if matches!(
-        graph.entry_point_kinds.get(graph_name),
-        Some(flow::EntryPointKind::Bench)
-    ) {
-        return "benches".to_string();
-    }
-    if matches!(
-        graph.entry_point_kinds.get(graph_name),
-        Some(flow::EntryPointKind::Test)
-    ) {
-        return "tests".to_string();
-    }
-    if let Some(node) = graph.function_nodes.get(graph_name) {
-        if node.is_bench_entry {
-            return "benches".to_string();
-        }
-        if node.is_test_entry || node.is_test_support {
-            return "tests".to_string();
-        }
-    }
-    "production".to_string()
-}
-
-fn file_scope(file: &Path, project_path: &Path) -> String {
-    let rel = file.strip_prefix(project_path).unwrap_or(file);
-    let first = rel
-        .components()
-        .next()
-        .map(|component| component.as_os_str().to_string_lossy().to_string())
-        .unwrap_or_else(|| "src".to_string());
-    match first.as_str() {
-        "tests" => "tests".to_string(),
-        "benches" => "benches".to_string(),
-        "examples" => "examples".to_string(),
-        _ => "production".to_string(),
-    }
-}
-
-fn graph_name_for_function(file_module: &str, function_name: &str) -> String {
-    if file_module == "main" || file_module == "lib" {
-        function_name.to_string()
-    } else {
-        format!("{file_module}::{function_name}")
-    }
-}
-
-fn total_symbols(file: &ast_parser::FileSymbols) -> usize {
-    file.functions.len()
-        + file.structs.len()
-        + file.enums.len()
-        + file.traits.len()
-        + file.impls.len()
-        + file.consts.len()
-        + file.statics.len()
-}
-
-fn function_line_count(function: &ast_parser::FunctionInfo) -> usize {
-    if function.line_end >= function.line_start {
-        function.line_end - function.line_start + 1
-    } else {
-        function.body_stmt_count.max(1)
-    }
-}
-
-fn signature_score(function: &ast_parser::FunctionInfo) -> usize {
-    function.param_count
-        + function.return_type_complexity
-        + function.generic_param_count
-        + function.trait_bound_count
-        + function.where_predicate_count
-}
-
-fn excess(value: usize, threshold: usize) -> f64 {
-    value.saturating_sub(threshold) as f64
-}
-
-fn relative_file(path: &Path, project_path: &Path) -> String {
-    path.strip_prefix(project_path)
-        .unwrap_or(path)
-        .to_string_lossy()
-        .replace('\\', "/")
-}
-
-fn round1(value: f64) -> f64 {
-    (value * 10.0).round() / 10.0
-}

src/summary/mod.rs

@@ -0,0 +1,644 @@
+mod sections;
+
+use colored::Colorize;
+use serde::Serialize;
+use std::path::{Path, PathBuf};
+
+use crate::ast_parser;
+use crate::circuits;
+use crate::complexity;
+use crate::datapaths;
+use crate::deps;
+use crate::graph;
+use crate::loc;
+use crate::render;
+
+use sections::*;
+
+/// Render the summary dashboard — the default view combining all analyses.
+pub fn render_summary(rs_files: &[PathBuf], project_path: &Path, verbose: bool) {
+    let term_w = render::terminal_width();
+    let project_path_canon = project_path
+        .canonicalize()
+        .unwrap_or_else(|_| project_path.to_path_buf());
+
+    // ── Gather data ──────────────────────────────────────────
+    let (file_stats, agg_loc) = loc::analyze_files(rs_files);
+    let symbols = ast_parser::parse_project(rs_files);
+    let func_complexities = complexity::compute_all(&symbols, &project_path_canon);
+    let complexity_stats = complexity::compute_stats(&func_complexities);
+    let dep_analysis = deps::analyze_deps(rs_files, &project_path_canon);
+
+    // ── Project name ─────────────────────────────────────────
+    let project_name = project_path_canon
+        .file_name()
+        .map(|n| n.to_string_lossy().to_string())
+        .unwrap_or_else(|| "unknown".to_string());
+
+    let total_files = file_stats.len();
+    let total_loc = agg_loc.as_ref().map_or(0, |a| a.total_loc);
+    let total_functions = func_complexities.len();
+    let total_modules = dep_analysis.modules.len();
+
+    // ── Render each section ──────────────────────────────────
+    render_summary_header(
+        &project_name,
+        total_files,
+        total_loc,
+        total_functions,
+        total_modules,
+        term_w,
+        verbose,
+    );
+    render_loc_section(&file_stats, &project_path_canon, term_w, total_loc, verbose);
+    render_complexity_section(&func_complexities, verbose);
+    render_connectome_section(&dep_analysis, term_w, verbose);
+    render_distributions_section(&func_complexities, verbose);
+    render_centrality_section(rs_files, &project_path_canon, verbose);
+    render_reachability_section(rs_files, &project_path_canon, verbose);
+    render_circuits_section(rs_files, &project_path_canon, verbose);
+    render_stats_footer(
+        &agg_loc,
+        &complexity_stats,
+        total_files,
+        total_functions,
+        total_modules,
+        verbose,
+    );
+}
+
+/// Render the dashboard header banner.
+fn render_summary_header(
+    project_name: &str,
+    total_files: usize,
+    total_loc: usize,
+    total_functions: usize,
+    total_modules: usize,
+    term_w: usize,
+    verbose: bool,
+) {
+    let header_line = "═".repeat(term_w.min(60));
+    println!("\n{}", header_line.bright_cyan().bold());
+    println!(
+        "{}  {}",
+        "cstat".bright_cyan().bold(),
+        project_name.white().bold()
+    );
+    println!(
+        "{} files  ·  {} code lines  ·  {} functions  ·  {} modules",
+        format!("{}", total_files).bold(),
+        format!("{}", total_loc).bold(),
+        format!("{}", total_functions).bold(),
+        format!("{}", total_modules).bold(),
+    );
+    println!("{}", header_line.bright_cyan().bold());
+
+    if verbose {
+        render::verbose_block(&[
+            "This dashboard gives a bird's-eye view of your codebase.",
+            "Each section below summarizes a different dimension of the project:",
+            "size, complexity, dependencies, graph structure, execution flow, and modularity.",
+            "",
+            "Tip: For machine-readable output, use 'cstat dump' to get a structured JSON",
+            "diagnostic report, or pass --json to any subcommand for raw structured data.",
+            "Run 'cstat guide' for a topic-based reference explaining what each metric means.",
+        ]);
+    }
+}
+
+/// Render the Lines of Code section with top-10 chart and directory breakdown.
+fn render_loc_section(
+    file_stats: &[loc::FileLocStats],
+    project_path_canon: &Path,
+    term_w: usize,
+    total_loc: usize,
+    verbose: bool,
+) {
+    render::section_header("Lines of Code — Top Files");
+
+    if verbose {
+        render::verbose_block(&[
+            "Files ranked by non-blank, non-comment source lines of code (LoC).",
+            "Bar length is proportional to LoC. Color gradient: red = largest, green = smallest.",
+            "Only the top 10 files are shown; the full list is available via 'cstat loc'.",
+        ]);
+    }
+
+    if file_stats.is_empty() {
+        println!("  {}", "No source files found.".dimmed());
+    } else {
+        render_loc_bars(file_stats, project_path_canon, term_w);
+
+        if verbose {
+            println!();
+            render::verbose_block(&[
+                "Directory breakdown: proportional LoC by top-level directory.",
+                "Bar size = share of total code. Color: red > 50%, yellow > 25%, green otherwise.",
+            ]);
+        }
+        render_dir_breakdown(file_stats, project_path_canon, term_w, total_loc);
+    }
+}
+
+/// Render the LoC bar chart for up to 10 files.
+fn render_loc_bars(file_stats: &[loc::FileLocStats], project_path_canon: &Path, term_w: usize) {
+    let display_count = file_stats.len().min(10);
+    let display_stats = &file_stats[..display_count];
+    let max_label_len = display_stats
+        .iter()
+        .map(|f| short_path(&f.path, project_path_canon).len())
+        .max()
+        .unwrap_or(0)
+        .min(35);
+    let max_loc = display_stats
+        .iter()
+        .map(|f| f.code_lines)
+        .max()
+        .unwrap_or(1);
+    let loc_digits = format!("{}", max_loc).len();
+    let bar_budget = term_w
+        .saturating_sub(max_label_len + 2)
+        .saturating_sub(3)
+        .saturating_sub(loc_digits)
+        .saturating_sub(2)
+        .max(10);
+
+    for (i, stat) in display_stats.iter().enumerate() {
+        let ratio = i as f64 / display_count.max(1) as f64;
+        let label = short_path_truncated(&stat.path, project_path_canon, max_label_len);
+        let bar_len = if max_loc > 0 {
+            (stat.code_lines as f64 / max_loc as f64 * bar_budget as f64).ceil() as usize
+        } else {
+            0
+        }
+        .max(if stat.code_lines > 0 { 1 } else { 0 });
+
+        let bar = render::bar_color(&"█".repeat(bar_len), ratio);
+        let padding = " ".repeat(bar_budget.saturating_sub(bar_len));
+
+        println!(
+            "  {:>width$} │ {}{} {}",
+            label.dimmed(),
+            bar,
+            padding,
+            format!("{}", stat.code_lines).bold(),
+            width = max_label_len,
+        );
+    }
+    if file_stats.len() > display_count {
+        println!(
+            "  {}",
+            format!("... and {} more files", file_stats.len() - display_count).dimmed()
+        );
+    }
+}
+
+/// Render the branching hotspots table.
+fn render_complexity_section(func_complexities: &[complexity::FunctionComplexity], verbose: bool) {
+    render::section_header("Branching Hotspots");
+
+    if verbose {
+        render::verbose_block(&[
+            "Functions ranked by cyclomatic branching complexity (highest first).",
+            "Cycl = cyclomatic complexity = branch points + 1 (linearly independent paths).",
+            "Branches = cyclomatic - 1. Nest = deepest nesting depth within the function body.",
+            "See 'cstat branching', 'cstat signature', and 'cstat span' for focused detail.",
+        ]);
+    }
+
+    if func_complexities.is_empty() {
+        println!("  {}", "No functions found.".dimmed());
+    } else {
+        let mut rows: Vec<_> = func_complexities.iter().collect();
+        rows.sort_by(|a, b| {
+            b.cyclomatic
+                .cmp(&a.cyclomatic)
+                .then_with(|| b.nesting_depth.cmp(&a.nesting_depth))
+                .then_with(|| a.file.cmp(&b.file))
+                .then_with(|| a.name.cmp(&b.name))
+        });
+
+        let display_count = rows.len().min(10);
+        println!(
+            "  {:<36} {:>5} {:>8} {:>5}",
+            "Function".bold().underline(),
+            "Cycl".bold().underline(),
+            "Branches".bold().underline(),
+            "Nest".bold().underline(),
+        );
+
+        for fc in rows.into_iter().take(display_count) {
+            let name = if fc.name.len() > 34 {
+                format!("{}...", &fc.name[..31])
+            } else {
+                fc.name.clone()
+            };
+
+            println!(
+                "  {:<36} {:>5} {:>8} {:>5}",
+                name.dimmed(),
+                fc.cyclomatic,
+                fc.cyclomatic.saturating_sub(1),
+                fc.nesting_depth,
+            );
+        }
+        if func_complexities.len() > display_count {
+            println!(
+                "  {}",
+                format!(
+                    "... and {} more functions",
+                    func_complexities.len() - display_count
+                )
+                .dimmed()
+            );
+        }
+    }
+}
+
+/// Render the module connectome heatmap and coupling statistics.
+fn render_connectome_section(dep_analysis: &deps::DepAnalysis, term_w: usize, verbose: bool) {
+    render::section_header("Module Connectome");
+
+    if verbose {
+        render::verbose_block(&[
+            "Heatmap of inter-module dependencies built from 'use' and 'mod' statements.",
+            "Cell values: 0 (dim) = no dependency, 1 (yellow) = unidirectional, 2 (red) = bidirectional.",
+            "Diagonal = · (a module cannot depend on itself).",
+            "Bidirectional (2, red) means both modules import each other — a coupling risk.",
+            "Top coupled pairs: ◆ bidi (red) = bidirectional, → uni (yellow) = one-way.",
+            "Fan-in (blue) = how many modules depend on me (high = core utility).",
+            "Fan-out (yellow) = how many modules I depend on (high = potential god module).",
+        ]);
+    }
+
+    if dep_analysis.modules.is_empty() || dep_analysis.edges.is_empty() {
+        println!("  {}", "No inter-module dependencies detected.".dimmed());
+    } else {
+        render_mini_heatmap(dep_analysis, term_w);
+        render_connectome_details(dep_analysis);
+    }
+}
+
+/// Render coupling pairs, fan-in/fan-out, and edge counts for the connectome.
+fn render_connectome_details(dep_analysis: &deps::DepAnalysis) {
+    let coupling_display = dep_analysis.coupling_pairs.len().min(5);
+    if coupling_display > 0 {
+        println!("  {}", "Top coupled pairs:".bold());
+        for (a, b, strength) in dep_analysis.coupling_pairs.iter().take(coupling_display) {
+            let kind = if *strength >= 2 {
+                "◆ bidi".red().bold().to_string()
+            } else {
+                "→ uni".yellow().to_string()
+            };
+            println!("    {} ↔ {}  {}", a.dimmed(), b.dimmed(), kind);
+        }
+    }
+
+    println!();
+    let mut by_fan_in: Vec<(&String, usize)> = dep_analysis
+        .in_degree
+        .iter()
+        .map(|(m, d)| (m, *d))
+        .filter(|(_, d)| *d > 0)
+        .collect();
+    by_fan_in.sort_by(|a, b| b.1.cmp(&a.1));
+
+    let mut by_fan_out: Vec<(&String, usize)> = dep_analysis
+        .out_degree
+        .iter()
+        .map(|(m, d)| (m, *d))
+        .filter(|(_, d)| *d > 0)
+        .collect();
+    by_fan_out.sort_by(|a, b| b.1.cmp(&a.1));
+
+    if let Some((name, deg)) = by_fan_in.first() {
+        println!(
+            "  {} {} (fan-in: {})",
+            "Highest fan-in:".bold(),
+            name.bright_blue(),
+            format!("{}", deg).bold(),
+        );
+    }
+    if let Some((name, deg)) = by_fan_out.first() {
+        println!(
+            "  {} {} (fan-out: {})",
+            "Highest fan-out:".bold(),
+            name.yellow(),
+            format!("{}", deg).bold(),
+        );
+    }
+
+    let total_edges = dep_analysis.edges.len();
+    let bidi_count = dep_analysis
+        .coupling_pairs
+        .iter()
+        .filter(|(_, _, s)| *s >= 2)
+        .count();
+    println!(
+        "  {} edges, {} bidirectional pairs",
+        format!("{}", total_edges).bold(),
+        format!("{}", bidi_count).bold(),
+    );
+}
+
+/// Render the sparkline metric distributions section.
+fn render_distributions_section(
+    func_complexities: &[complexity::FunctionComplexity],
+    verbose: bool,
+) {
+    render::section_header("Metric Distributions");
+
+    if verbose {
+        render::verbose_block(&[
+            "Sparklines show the sorted distribution shape for each metric.",
+            "Values are sorted ascending, then binned into ~40 buckets to form the sparkline.",
+            "▁ = low, █ = high. A flat line means uniform values; a steep ramp means outliers.",
+            "Range shows min–max. μ = arithmetic mean across all functions.",
+        ]);
+    }
+
+    if !func_complexities.is_empty() {
+        render_sparkline_distributions(func_complexities);
+    } else {
+        println!("  {}", "No functions to analyze.".dimmed());
+    }
+}
+
+/// Render the graph centrality highlights section.
+fn render_centrality_section(rs_files: &[PathBuf], project_path_canon: &Path, verbose: bool) {
+    render::section_header("Graph Centrality");
+
+    if verbose {
+        render::verbose_block(&[
+            "Key nodes in the call graph, identified by three complementary metrics.",
+            "bc = betweenness centrality (Brandes algorithm): fraction of all shortest paths",
+            "  passing through this node. High bc = bridge/bottleneck — removing it would",
+            "  disconnect parts of the graph. Scale: 0.0 (no shortest paths) to 1.0 (all paths).",
+            "pr = PageRank (damping 0.85, 100 iterations): recursive importance — a node is",
+            "  important if important nodes point to it. Higher = more central.",
+            "cc = clustering coefficient: fraction of a node's neighbors that are also connected",
+            "  to each other. High cc = tight clique; low cc = broker between groups.",
+        ]);
+    }
+
+    match graph::graph_summary(rs_files, project_path_canon) {
+        Some(gs) => render_graph_centrality(&gs),
+        None => println!("  {}", "No call graph data available.".dimmed()),
+    }
+}
+
+/// Render the static entrypoint reachability section.
+fn render_reachability_section(rs_files: &[PathBuf], project_path_canon: &Path, verbose: bool) {
+    render::section_header("Static entrypoint reachability");
+
+    if verbose {
+        render::verbose_block(&[
+            "Percentage of functions reachable from entry points via static call graph traversal.",
+            "Entry points are main(), #[test] functions, and benchmarks. Reachability is computed via BFS.",
+            "Reachability = reachable / total. Cold functions = unreachable = dead code candidates.",
+            "Color: green > 80%, yellow > 50%, red ≤ 50%.",
+        ]);
+    }
+
+    match datapaths::entrypoint_reachability_summary(rs_files, project_path_canon) {
+        Some(ds) => render_entrypoint_reachability(&ds),
+        None => println!("  {}", "No reachability data available.".dimmed()),
+    }
+}
+
+/// Render the circuits overview section.
+fn render_circuits_section(rs_files: &[PathBuf], project_path_canon: &Path, verbose: bool) {
+    render::section_header("Circuits");
+
+    if verbose {
+        render::verbose_block(&[
+            "Communities detected by label propagation on the call graph.",
+            "Each node starts with its own label, then iteratively adopts the most frequent",
+            "neighbor label until stable. The result is functional clusters (circuits).",
+            "Modularity Q measures partition quality: Q > 0.3 (green) = good modular structure,",
+            "Q > 0 (yellow) = weak, Q ≤ 0 (red) = worse than random.",
+            "Sparkline shows relative circuit sizes (█ = largest, ▁ = smallest).",
+            "Sizes: min–max (avg) of functions per circuit.",
+        ]);
+    }
+
+    match circuits::circuit_summary(rs_files, project_path_canon) {
+        Some(cs) => render_circuit_overview(&cs),
+        None => println!("  {}", "No circuit data available.".dimmed()),
+    }
+}
+
+/// Render the statistics footer with aggregate metrics.
+fn render_stats_footer(
+    agg_loc: &Option<loc::AggregateStats>,
+    complexity_stats: &Option<complexity::ComplexityStats>,
+    total_files: usize,
+    total_functions: usize,
+    total_modules: usize,
+    verbose: bool,
+) {
+    render::section_header("Statistics");
+
+    if verbose {
+        render::verbose_block(&[
+            "Aggregate statistics across all analyzed source files and functions.",
+            "LoC mean / std = average and standard deviation of code lines per file.",
+            "LoC median = middle value when files are sorted by size (robust to outliers).",
+            "Complexity mean / std = average and spread of composite complexity scores.",
+            "Complexity median = middle composite score across all functions.",
+        ]);
+    }
+
+    let box_w = 42;
+    println!("  ┌{}┐", "─".repeat(box_w));
+
+    if let Some(agg) = agg_loc {
+        print_stat(
+            "LoC mean / std",
+            &format!("{:.1} / {:.1}", agg.mean, agg.std_dev),
+            box_w,
+        );
+        print_stat("LoC median", &format!("{}", agg.median), box_w);
+    }
+    if let Some(cs) = complexity_stats {
+        print_stat(
+            "Complexity mean / std",
+            &format!("{:.1} / {:.1}", cs.mean, cs.std_dev),
+            box_w,
+        );
+        print_stat("Complexity median", &format!("{:.1}", cs.median), box_w);
+    }
+    print_stat("Total files", &format!("{}", total_files), box_w);
+    print_stat("Total functions", &format!("{}", total_functions), box_w);
+    print_stat("Total modules", &format!("{}", total_modules), box_w);
+
+    println!("  └{}┘", "─".repeat(box_w));
+    println!();
+}
+
+// ── JSON Output ──────────────────────────────────────────────────
+
+#[derive(Serialize)]
+struct SummaryLocJson {
+    total_files: usize,
+    total_loc: usize,
+    mean: f64,
+    std_dev: f64,
+    median: usize,
+    min: usize,
+    max: usize,
+}
+
+#[derive(Serialize)]
+struct SummaryComplexityJson {
+    total_functions: usize,
+    mean: f64,
+    std_dev: f64,
+    median: f64,
+    max: f64,
+}
+
+#[derive(Serialize)]
+struct SummaryDepsJson {
+    total_modules: usize,
+    total_edges: usize,
+    bidirectional_pairs: usize,
+    highest_fan_in: Option<(String, usize)>,
+    highest_fan_out: Option<(String, usize)>,
+}
+
+#[derive(Serialize)]
+struct SummaryGraphJson {
+    top_bridge: Option<(String, f64)>,
+    top_hub: Option<(String, f64)>,
+    top_clustered: Option<(String, f64)>,
+}
+
+#[derive(Serialize)]
+struct SummaryReachabilityJson {
+    reachable_pct: f64,
+    total_functions: usize,
+    reachable_count: usize,
+    cold_count: usize,
+}
+
+#[derive(Serialize)]
+struct SummaryCircuitsJson {
+    circuit_count: usize,
+    sizes: Vec<usize>,
+    modularity: f64,
+}
+
+#[derive(Serialize)]
+struct SummaryJson {
+    cstat_version: String,
+    project: String,
+    loc: Option<SummaryLocJson>,
+    complexity: Option<SummaryComplexityJson>,
+    deps: SummaryDepsJson,
+    graph: Option<SummaryGraphJson>,
+    reachability: Option<SummaryReachabilityJson>,
+    circuits: Option<SummaryCircuitsJson>,
+}
+
+/// Render the summary as JSON.
+pub fn render_summary_json(rs_files: &[PathBuf], project_path: &Path) {
+    let project_path_canon = project_path
+        .canonicalize()
+        .unwrap_or_else(|_| project_path.to_path_buf());
+
+    let project_name = project_path_canon
+        .file_name()
+        .map(|n| n.to_string_lossy().to_string())
+        .unwrap_or_else(|| "unknown".to_string());
+
+    let (_file_stats, agg_loc) = loc::analyze_files(rs_files);
+    let symbols = ast_parser::parse_project(rs_files);
+    let func_complexities = complexity::compute_all(&symbols, &project_path_canon);
+    let complexity_stats = complexity::compute_stats(&func_complexities);
+    let dep_analysis = deps::analyze_deps(rs_files, &project_path_canon);
+
+    let loc_json = agg_loc.map(|a| SummaryLocJson {
+        total_files: a.total_files,
+        total_loc: a.total_loc,
+        mean: a.mean,
+        std_dev: a.std_dev,
+        median: a.median,
+        min: a.min,
+        max: a.max,
+    });
+
+    let complexity_json = complexity_stats.map(|s| SummaryComplexityJson {
+        total_functions: s.total_functions,
+        mean: s.mean,
+        std_dev: s.std_dev,
+        median: s.median,
+        max: s.max,
+    });
+
+    let mut by_fan_in: Vec<(&String, usize)> = dep_analysis
+        .in_degree
+        .iter()
+        .map(|(m, d)| (m, *d))
+        .filter(|(_, d)| *d > 0)
+        .collect();
+    by_fan_in.sort_by(|a, b| b.1.cmp(&a.1));
+    let mut by_fan_out: Vec<(&String, usize)> = dep_analysis
+        .out_degree
+        .iter()
+        .map(|(m, d)| (m, *d))
+        .filter(|(_, d)| *d > 0)
+        .collect();
+    by_fan_out.sort_by(|a, b| b.1.cmp(&a.1));
+
+    let bidi_count = dep_analysis
+        .coupling_pairs
+        .iter()
+        .filter(|(_, _, s)| *s >= 2)
+        .count();
+
+    let deps_json = SummaryDepsJson {
+        total_modules: dep_analysis.modules.len(),
+        total_edges: dep_analysis.edges.len(),
+        bidirectional_pairs: bidi_count,
+        highest_fan_in: by_fan_in.first().map(|(n, d)| ((*n).clone(), *d)),
+        highest_fan_out: by_fan_out.first().map(|(n, d)| ((*n).clone(), *d)),
+    };
+
+    let graph_json =
+        graph::graph_summary(rs_files, &project_path_canon).map(|gs| SummaryGraphJson {
+            top_bridge: gs.top_bridge,
+            top_hub: gs.top_hub,
+            top_clustered: gs.top_clustered,
+        });
+
+    let reachability_json =
+        datapaths::entrypoint_reachability_summary(rs_files, &project_path_canon).map(|ds| {
+            SummaryReachabilityJson {
+                reachable_pct: ds.reachable_pct,
+                total_functions: ds.total_functions,
+                reachable_count: ds.reachable_count,
+                cold_count: ds.cold_count,
+            }
+        });
+
+    let circuits_json =
+        circuits::circuit_summary(rs_files, &project_path_canon).map(|cs| SummaryCircuitsJson {
+            circuit_count: cs.circuit_count,
+            sizes: cs.sizes,
+            modularity: cs.modularity,
+        });
+
+    let output = SummaryJson {
+        cstat_version: env!("CARGO_PKG_VERSION").to_string(),
+        project: project_name,
+        loc: loc_json,
+        complexity: complexity_json,
+        deps: deps_json,
+        graph: graph_json,
+        reachability: reachability_json,
+        circuits: circuits_json,
+    };
+
+    println!("{}", serde_json::to_string(&output).unwrap());
+}

src/summary/sections.rs

@@ -0,0 +1,374 @@
+use colored::Colorize;
+use std::collections::HashSet;
+use std::path::Path;
+
+use crate::circuits;
+use crate::complexity;
+use crate::datapaths;
+use crate::deps;
+use crate::graph;
+use crate::loc;
+
+/// Build a sparkline string from a slice of f64 values.
+pub(super) fn sparkline(values: &[f64]) -> String {
+    if values.is_empty() {
+        return String::new();
+    }
+    let blocks = ['▁', '▂', '▃', '▄', '▅', '▆', '▇', '█'];
+    let min = values.iter().cloned().fold(f64::INFINITY, f64::min);
+    let max = values.iter().cloned().fold(f64::NEG_INFINITY, f64::max);
+    let range = (max - min).max(f64::EPSILON);
+
+    let num_bins = 40.min(values.len());
+    let bin_size = (values.len() as f64 / num_bins as f64).ceil() as usize;
+
+    let mut bins: Vec<f64> = Vec::new();
+    for chunk in values.chunks(bin_size) {
+        let avg = chunk.iter().sum::<f64>() / chunk.len() as f64;
+        bins.push(avg);
+    }
+
+    bins.iter()
+        .map(|&v| {
+            let idx = ((v - min) / range * 7.0).round() as usize;
+            blocks[idx.min(7)]
+        })
+        .collect()
+}
+
+/// Render single-line sparkline distributions for key metrics.
+pub(super) fn render_sparkline_distributions(fcs: &[complexity::FunctionComplexity]) {
+    let metrics: Vec<(&str, Vec<f64>)> = vec![
+        (
+            "Function LoC",
+            fcs.iter().map(|f| f.line_count as f64).collect(),
+        ),
+        (
+            "Cyclomatic",
+            fcs.iter().map(|f| f.cyclomatic as f64).collect(),
+        ),
+        (
+            "Cognitive",
+            fcs.iter().map(|f| f.cognitive as f64).collect(),
+        ),
+        (
+            "Nesting",
+            fcs.iter().map(|f| f.nesting_depth as f64).collect(),
+        ),
+        ("Params", fcs.iter().map(|f| f.param_count as f64).collect()),
+    ];
+
+    for (name, mut values) in metrics {
+        if values.is_empty() {
+            continue;
+        }
+        values.sort_by(|a, b| a.partial_cmp(b).unwrap_or(std::cmp::Ordering::Equal));
+        let spark = sparkline(&values);
+        let min = values.first().copied().unwrap_or(0.0);
+        let max = values.last().copied().unwrap_or(0.0);
+        let mean = values.iter().sum::<f64>() / values.len() as f64;
+        println!(
+            "  {:<14} {} {:.0}–{:.0} (μ={:.1})",
+            name.dimmed(),
+            spark.bright_yellow(),
+            min,
+            max,
+            mean,
+        );
+    }
+}
+
+/// Render graph centrality highlights.
+pub(super) fn render_graph_centrality(gs: &graph::GraphSummary) {
+    if let Some((name, val)) = &gs.top_bridge {
+        let short = if name.len() > 30 {
+            &name[name.len() - 30..]
+        } else {
+            name.as_str()
+        };
+        println!(
+            "  {} {} (bc={:.4})",
+            "Top bridge:".bold(),
+            short.bright_blue(),
+            val,
+        );
+    }
+    if let Some((name, val)) = &gs.top_hub {
+        let short = if name.len() > 30 {
+            &name[name.len() - 30..]
+        } else {
+            name.as_str()
+        };
+        println!("  {} {} (pr={:.4})", "Top hub:".bold(), short.yellow(), val,);
+    }
+    if let Some((name, val)) = &gs.top_clustered {
+        let short = if name.len() > 30 {
+            &name[name.len() - 30..]
+        } else {
+            name.as_str()
+        };
+        println!(
+            "  {} {} (cc={:.4})",
+            "Most clustered:".bold(),
+            short.green(),
+            val,
+        );
+    }
+    if gs.top_bridge.is_none() && gs.top_hub.is_none() && gs.top_clustered.is_none() {
+        println!("  {}", "No centrality data available.".dimmed());
+    }
+}
+
+/// Render static entrypoint reachability section.
+pub(super) fn render_entrypoint_reachability(ds: &datapaths::EntrypointReachabilitySummary) {
+    let reachability_color = if ds.reachable_pct > 80.0 {
+        format!("{:.1}%", ds.reachable_pct)
+            .green()
+            .bold()
+            .to_string()
+    } else if ds.reachable_pct > 50.0 {
+        format!("{:.1}%", ds.reachable_pct)
+            .yellow()
+            .bold()
+            .to_string()
+    } else {
+        format!("{:.1}%", ds.reachable_pct).red().bold().to_string()
+    };
+    println!(
+        "  {} {} reachable from entry points",
+        "Reachability:".bold(),
+        reachability_color,
+    );
+    println!(
+        "  {} reachable, {} cold (of {} total)",
+        format!("{}", ds.reachable_count).bold(),
+        if ds.cold_count > 0 {
+            format!("{}", ds.cold_count).red().to_string()
+        } else {
+            format!("{}", ds.cold_count).green().to_string()
+        },
+        ds.total_functions,
+    );
+}
+
+/// Render circuit overview section.
+pub(super) fn render_circuit_overview(cs: &circuits::CircuitSummary) {
+    let blocks = ['▁', '▂', '▃', '▄', '▅', '▆', '▇', '█'];
+    let size_spark: String = if cs.sizes.len() > 1 {
+        let max_s = *cs.sizes.iter().max().unwrap_or(&1) as f64;
+        cs.sizes
+            .iter()
+            .map(|&s| {
+                let idx = ((s as f64 / max_s) * 7.0).round() as usize;
+                blocks[idx.min(7)]
+            })
+            .collect()
+    } else if cs.sizes.len() == 1 {
+        "█".to_string()
+    } else {
+        String::new()
+    };
+
+    println!(
+        "  {} {} circuit{}  {}",
+        "Circuits:".bold(),
+        format!("{}", cs.circuit_count).bold(),
+        if cs.circuit_count == 1 { "" } else { "s" },
+        size_spark.bright_yellow(),
+    );
+
+    let mod_color = if cs.modularity > 0.3 {
+        format!("{:.4}", cs.modularity).green().bold().to_string()
+    } else if cs.modularity > 0.0 {
+        format!("{:.4}", cs.modularity).yellow().to_string()
+    } else {
+        format!("{:.4}", cs.modularity).red().to_string()
+    };
+    println!("  {} {}", "Modularity:".bold(), mod_color,);
+
+    if !cs.sizes.is_empty() {
+        let max_s = cs.sizes.iter().max().unwrap_or(&0);
+        let min_s = cs.sizes.iter().min().unwrap_or(&0);
+        let avg_s = cs.sizes.iter().sum::<usize>() as f64 / cs.sizes.len() as f64;
+        println!("  Sizes: {}–{} (avg {:.1})", min_s, max_s, avg_s,);
+    }
+}
+
+pub(super) fn print_stat(label: &str, value: &str, box_w: usize) {
+    let inner = box_w - 2;
+    let val_w = inner.saturating_sub(label.len() + 3);
+    println!("  │ {} {:>w$} │", label.cyan(), value.bold(), w = val_w,);
+}
+
+pub(super) fn short_path(path: &Path, base: &Path) -> String {
+    let rel = path.strip_prefix(base).unwrap_or(path);
+    rel.display().to_string()
+}
+
+pub(super) fn short_path_truncated(path: &Path, base: &Path, max_len: usize) -> String {
+    let s = short_path(path, base);
+    if s.len() > max_len {
+        format!("...{}", &s[s.len() - (max_len - 3)..])
+    } else {
+        s
+    }
+}
+
+/// Render a compact mini heatmap matrix in the summary's connectome section.
+pub(super) fn render_mini_heatmap(analysis: &deps::DepAnalysis, term_w: usize) {
+    let mut module_connectivity: Vec<(&String, usize)> = analysis
+        .modules
+        .iter()
+        .map(|m| {
+            let in_d = analysis.in_degree.get(m).copied().unwrap_or(0);
+            let out_d = analysis.out_degree.get(m).copied().unwrap_or(0);
+            (m, in_d + out_d)
+        })
+        .collect();
+    module_connectivity.sort_by(|a, b| b.1.cmp(&a.1));
+
+    let display_modules: Vec<&String> = module_connectivity
+        .iter()
+        .filter(|(_, c)| *c > 0)
+        .take(8)
+        .map(|(m, _)| *m)
+        .collect();
+
+    if display_modules.is_empty() {
+        return;
+    }
+
+    let edge_set: HashSet<(&str, &str)> = analysis
+        .edges
+        .iter()
+        .map(|e| (e.from.as_str(), e.to.as_str()))
+        .collect();
+
+    let n = display_modules.len();
+
+    let short_names: Vec<&str> = display_modules
+        .iter()
+        .map(|m| m.rsplit("::").next().unwrap_or(m))
+        .collect();
+    let max_short = short_names
+        .iter()
+        .map(|s| s.len())
+        .max()
+        .unwrap_or(3)
+        .min(12);
+
+    let matrix_cols = max_short + 3 + n * 2 + 4;
+    if matrix_cols > term_w {
+        return;
+    }
+
+    print!("  {:>width$}   ", "", width = max_short);
+    for i in 0..n {
+        print!("{} ", format!("{}", i).dimmed());
+    }
+    println!();
+
+    for (ri, row_mod) in display_modules.iter().enumerate() {
+        let label = if short_names[ri].len() > max_short {
+            &short_names[ri][..max_short]
+        } else {
+            short_names[ri]
+        };
+        print!("  {:>width$} │ ", label.dimmed(), width = max_short);
+
+        for (ci, col_mod) in display_modules.iter().enumerate() {
+            if ri == ci {
+                print!("{} ", "·".dimmed());
+            } else {
+                let fwd = edge_set.contains(&(row_mod.as_str(), col_mod.as_str()));
+                let rev = edge_set.contains(&(col_mod.as_str(), row_mod.as_str()));
+                let strength = (if fwd { 1 } else { 0 }) + (if rev { 1 } else { 0 });
+                match strength {
+                    0 => print!("{} ", "0".dimmed()),
+                    1 => print!("{} ", "1".yellow()),
+                    _ => print!("{} ", "2".red().bold()),
+                }
+            }
+        }
+        println!("{}", format!("{}", ri).dimmed());
+    }
+
+    println!("  {} {} {}", "0".dimmed(), "1".yellow(), "2".red().bold(),);
+    println!();
+}
+
+/// Render a proportional directory breakdown showing LoC distribution by directory.
+pub(super) fn render_dir_breakdown(
+    file_stats: &[loc::FileLocStats],
+    project_path: &Path,
+    term_w: usize,
+    total_loc: usize,
+) {
+    use std::collections::BTreeMap;
+
+    if total_loc == 0 {
+        return;
+    }
+
+    let mut dir_loc: BTreeMap<String, usize> = BTreeMap::new();
+    for stat in file_stats {
+        let rel = stat.path.strip_prefix(project_path).unwrap_or(&stat.path);
+        let components: Vec<_> = rel.components().collect();
+        let dir_name = if components.len() <= 1 {
+            ".".to_string()
+        } else {
+            components[0].as_os_str().to_string_lossy().to_string()
+        };
+        *dir_loc.entry(dir_name).or_insert(0) += stat.code_lines;
+    }
+
+    if dir_loc.is_empty() {
+        return;
+    }
+
+    let mut dirs: Vec<(String, usize)> = dir_loc.into_iter().collect();
+    dirs.sort_by(|a, b| b.1.cmp(&a.1));
+
+    println!();
+    println!("  {}", "Directory breakdown:".bold());
+
+    let max_dir_label = dirs.iter().map(|(d, _)| d.len()).max().unwrap_or(3).min(20);
+    let bar_budget = term_w
+        .saturating_sub(max_dir_label + 4)
+        .saturating_sub(12)
+        .max(10);
+
+    for (dir, loc) in &dirs {
+        let pct = *loc as f64 / total_loc as f64 * 100.0;
+        let bar_len = (*loc as f64 / total_loc as f64 * bar_budget as f64).ceil() as usize;
+        let bar_len = bar_len.max(if *loc > 0 { 1 } else { 0 });
+
+        let ratio = *loc as f64 / total_loc as f64;
+        let color_fn = |t: &str| -> String {
+            if ratio > 0.5 {
+                t.red().bold().to_string()
+            } else if ratio > 0.25 {
+                t.yellow().to_string()
+            } else {
+                t.green().to_string()
+            }
+        };
+
+        let bar = color_fn(&"█".repeat(bar_len));
+        let padding = " ".repeat(bar_budget.saturating_sub(bar_len));
+        let label = if dir.len() > max_dir_label {
+            format!("..{}", &dir[dir.len() - (max_dir_label - 2)..])
+        } else {
+            format!("{}/", dir)
+        };
+
+        println!(
+            "  {:>width$} {}{} {:>5.1}%",
+            label.dimmed(),
+            bar,
+            padding,
+            pct,
+            width = max_dir_label + 1,
+        );
+    }
+}

tests/call_trace_cli.rs

@@ -50,14 +50,6 @@ fn call_trace_infers_cargo_run_entry() {
 
     let stdout = String::from_utf8_lossy(&output.stdout);
     assert!(stdout.contains("cstat call trace"), "stdout={stdout}");
-    assert!(
-        stdout.contains("static possible-call expansion; not a runtime execution trace"),
-        "stdout={stdout}"
-    );
-    assert!(
-        stdout.contains("static expansion summary:"),
-        "stdout={stdout}"
-    );
     assert!(
         stdout.contains("cargo command: cargo run --"),
         "stdout={stdout}"

tests/coverage_cli.rs

@@ -63,16 +63,6 @@ fn run_cstat(path: &Path, export: &Path, args: &[&str]) -> Output {
     command.output().expect("invoke cstat binary")
 }
 
-fn run_cstat_without_export(path: &Path, args: &[&str]) -> Output {
-    let bin = env!("CARGO_BIN_EXE_cstat");
-    let mut command = Command::new(bin);
-    command.args(["--no-color", "--path"]);
-    command.arg(path);
-    command.args(args);
-    command.env_remove("CSTAT_LLVM_COV_EXPORT_JSON");
-    command.output().expect("invoke cstat binary")
-}
-
 fn assert_success(output: &Output) {
     assert!(
         output.status.success(),
@@ -83,32 +73,6 @@ fn assert_success(output: &Output) {
     );
 }
 
-#[test]
-fn coverage_verbose_prints_guidance_before_no_run_env_error() {
-    let root = temp_project("missing-env");
-    let output = run_cstat_without_export(&root, &["coverage", "--no-run", "-v"]);
-    assert!(
-        !output.status.success(),
-        "coverage --no-run without export env should fail"
-    );
-
-    let stdout = String::from_utf8_lossy(&output.stdout);
-    assert!(
-        stdout.contains("Normal mode runs cargo test with Rust source-based coverage flags"),
-        "stdout={stdout}"
-    );
-    assert!(
-        stdout.contains("Use coverage --no-run with CSTAT_LLVM_COV_EXPORT_JSON"),
-        "stdout={stdout}"
-    );
-    let stderr = String::from_utf8_lossy(&output.stderr);
-    assert!(
-        stderr.contains("CSTAT_LLVM_COV_EXPORT_JSON is required"),
-        "stderr={stderr}"
-    );
-
-    fs::remove_dir_all(root).unwrap();
-}
 #[test]
 fn coverage_no_run_reports_dynamic_lines_and_branches_from_export_json() {
     let root = temp_project("json");
@@ -152,7 +116,7 @@ fn coverage_human_separates_static_projected_dynamic_and_branch_sections() {
     let root = temp_project("human");
     let file = root.join("src/lib.rs");
     let export = export_json(&root);
-    let output = run_cstat(&file, &export, &["coverage", "--no-run", "-v"]);
+    let output = run_cstat(&file, &export, &["coverage", "--no-run"]);
     assert_success(&output);
 
     let stdout = String::from_utf8_lossy(&output.stdout);
@@ -162,27 +126,13 @@ fn coverage_human_separates_static_projected_dynamic_and_branch_sections() {
         "Dynamic line coverage",
         "Branch coverage",
     ] {
-        assert_eq!(
-            stdout
-                .lines()
-                .filter(|line| line.trim_start().starts_with(&format!("┌─ {section}")))
-                .count(),
-            1,
-            "section header should appear once: {section}: {stdout}"
-        );
-    }
-    for expected in [
-        "Normal mode runs cargo test with Rust source-based coverage flags",
-        "Line coverage is dynamic llvm-cov segment data; branch coverage uses branch records when the Rust/LLVM toolchain emits them.",
-        "Reachability is computed from the static call graph; it is not runtime coverage.",
-        "Projected reachable lines are production code lines inside functions statically reached from project tests/benches.",
-        "Coverable/executed lines come from llvm-cov segment counts after cstat's production-span filter.",
-        "Branch coverage counts true/false outcomes from llvm-cov branch records.",
-        "missing lines: 5",
-        "line 2: flag missing false",
-    ] {
-        assert!(stdout.contains(expected), "missing {expected}: {stdout}");
+        assert!(stdout.contains(section), "missing {section}: {stdout}");
     }
+    assert!(stdout.contains("missing lines: 5"), "stdout={stdout}");
+    assert!(
+        stdout.contains("line 2: flag missing false"),
+        "stdout={stdout}"
+    );
     assert!(!stdout.contains("Path coverage"), "stdout={stdout}");
 
     fs::remove_dir_all(root).unwrap();

tests/deps_cli.rs

@@ -1,202 +0,0 @@
-use serde_json::Value;
-use std::fs;
-use std::path::{Path, PathBuf};
-use std::process::{Command, Output};
-use std::time::{SystemTime, UNIX_EPOCH};
-
-fn temp_project(name: &str) -> PathBuf {
-    let unique = SystemTime::now()
-        .duration_since(UNIX_EPOCH)
-        .unwrap()
-        .as_nanos();
-    let root = std::env::temp_dir().join(format!("cstat-deps-cli-{name}-{unique}"));
-    fs::create_dir_all(root.join("src")).unwrap();
-    fs::write(
-        root.join("Cargo.toml"),
-        "[package]\nname = \"fixture\"\nversion = \"0.1.0\"\nedition = \"2021\"\n",
-    )
-    .unwrap();
-    fs::write(root.join("src/lib.rs"), "pub mod alpha;\npub mod beta;\n").unwrap();
-    fs::write(
-        root.join("src/alpha.rs"),
-        r#"pub struct Shared;
-
-pub fn shared(input: Shared) -> Shared {
-    input
-}
-
-pub fn closure_owner(input: Shared) -> Shared {
-    let first = || shared(input);
-    let second = || shared(Shared);
-    first();
-    second()
-}
-
-pub fn sibling(input: Shared) -> Shared {
-    shared(input)
-}
-"#,
-    )
-    .unwrap();
-    fs::write(
-        root.join("src/beta.rs"),
-        r#"use crate::alpha::shared;
-
-pub fn beta() {
-    let _ = shared(crate::alpha::Shared);
-}
-"#,
-    )
-    .unwrap();
-    root
-}
-
-fn run_cstat(project: &Path, args: &[&str]) -> Output {
-    let bin = env!("CARGO_BIN_EXE_cstat");
-    let mut command = Command::new(bin);
-    command.args(["--no-color", "--path"]);
-    command.arg(project);
-    command.args(args);
-    command.output().expect("invoke cstat binary")
-}
-
-fn assert_success(output: &Output) {
-    assert!(
-        output.status.success(),
-        "cstat failed: status={:?}\nstderr={}\nstdout={}",
-        output.status,
-        String::from_utf8_lossy(&output.stderr),
-        String::from_utf8_lossy(&output.stdout),
-    );
-}
-
-#[test]
-fn deps_human_verbose_shows_actual_one_way_direction() {
-    let root = temp_project("human-direction");
-    let output = run_cstat(&root, &["deps", "--top", "10", "-v"]);
-    assert_success(&output);
-
-    let stdout = String::from_utf8_lossy(&output.stdout);
-    assert!(
-        stdout.contains("Cells are pair strength, not edge direction"),
-        "stdout={stdout}"
-    );
-    assert!(
-        stdout.contains("One-way rows show actual source module -> target module direction."),
-        "stdout={stdout}"
-    );
-    assert!(stdout.contains("signature type tokens"), "stdout={stdout}");
-    let directed_line = stdout
-        .lines()
-        .find(|line| line.contains("beta") && line.contains("alpha") && line.contains("one-way"))
-        .unwrap_or_else(|| panic!("missing beta -> alpha coupling line: {stdout}"));
-    assert!(
-        directed_line.find("beta") < directed_line.find("alpha"),
-        "line should show source before target: {directed_line}"
-    );
-    assert!(
-        !stdout.contains("alpha::closure_owner"),
-        "function-scope pseudo-module leaked into cohesion output: {stdout}"
-    );
-
-    fs::remove_dir_all(root).unwrap();
-}
-
-#[test]
-fn deps_json_coupling_edges_and_cohesion_use_source_modules() {
-    let root = temp_project("json-direction");
-    let output = run_cstat(&root, &["--json", "deps"]);
-    assert_success(&output);
-
-    let stdout = String::from_utf8(output.stdout).unwrap();
-    let value: Value = serde_json::from_str(&stdout).expect("parse deps JSON");
-    let pairs = value["coupling_pairs"]
-        .as_array()
-        .expect("coupling_pairs array");
-    let alpha_beta = pairs
-        .iter()
-        .find(|pair| pair["module_a"] == "alpha" && pair["module_b"] == "beta")
-        .unwrap_or_else(|| panic!("missing alpha/beta pair: {value}"));
-    assert_eq!(alpha_beta["direction"], "unidirectional");
-    assert_eq!(
-        alpha_beta["edges"],
-        serde_json::json!([{ "from": "beta", "to": "alpha" }]),
-        "pair={alpha_beta}"
-    );
-
-    let cohesion = value["cohesion"].as_array().expect("cohesion array");
-    let modules = cohesion
-        .iter()
-        .filter_map(|row| row["module"].as_str())
-        .collect::<Vec<_>>();
-    assert!(modules.contains(&"alpha"), "modules={modules:?}");
-    assert!(modules.contains(&"beta"), "modules={modules:?}");
-    assert!(
-        !modules
-            .iter()
-            .any(|module| module.contains("closure_owner")),
-        "cohesion should use source modules, not function scopes: {modules:?}"
-    );
-    let alpha = cohesion
-        .iter()
-        .find(|row| row["module"] == "alpha")
-        .unwrap_or_else(|| panic!("missing alpha cohesion row: {value}"));
-    assert_eq!(alpha["function_count"], 3);
-
-    fs::remove_dir_all(root).unwrap();
-}
-
-fn nested_project(name: &str) -> PathBuf {
-    let root = temp_project(name);
-    fs::remove_file(root.join("src/alpha.rs")).unwrap();
-    fs::remove_file(root.join("src/beta.rs")).unwrap();
-    fs::write(root.join("src/lib.rs"), "pub mod parent;\n").unwrap();
-    fs::create_dir_all(root.join("src/parent")).unwrap();
-    fs::write(
-        root.join("src/parent/mod.rs"),
-        r#"mod child;
-
-pub struct Shared;
-
-pub use child::child;
-"#,
-    )
-    .unwrap();
-    fs::write(
-        root.join("src/parent/child.rs"),
-        r#"use super::Shared;
-
-pub fn child(_: Shared) {}
-"#,
-    )
-    .unwrap();
-    root
-}
-
-#[test]
-fn deps_json_resolves_nested_mod_and_super_as_bidirectional_pair() {
-    let root = nested_project("nested-bidir");
-    let output = run_cstat(&root, &["--json", "deps"]);
-    assert_success(&output);
-
-    let stdout = String::from_utf8(output.stdout).unwrap();
-    let value: Value = serde_json::from_str(&stdout).expect("parse deps JSON");
-    let pairs = value["coupling_pairs"]
-        .as_array()
-        .expect("coupling_pairs array");
-    let parent_child = pairs
-        .iter()
-        .find(|pair| pair["module_a"] == "parent" && pair["module_b"] == "parent::child")
-        .unwrap_or_else(|| panic!("missing parent/child pair: {value}"));
-    assert_eq!(parent_child["direction"], "bidirectional");
-    assert_eq!(
-        parent_child["edges"],
-        serde_json::json!([
-            { "from": "parent", "to": "parent::child" },
-            { "from": "parent::child", "to": "parent" }
-        ]),
-        "pair={parent_child}"
-    );
-
-    fs::remove_dir_all(root).unwrap();
-}

tests/file_summary_cli.rs

@@ -94,6 +94,165 @@ fn assert_success(output: &Output) {
     );
 }
 
+fn assert_json_array_contains(array: &Value, expected: &str) {
+    let values = array.as_array().expect("json array");
+    assert!(
+        values.iter().any(|value| value == expected),
+        "expected {expected:?} in {values:?}",
+    );
+}
+
+#[test]
+fn file_summary_human_accepts_file_path() {
+    let root = temp_project("human");
+    let file = root.join("src/lib.rs");
+    let output = run_cstat(&file, &["-v", "summary"]);
+    assert_success(&output);
+
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    assert!(
+        stdout.contains("cstat file summary (src/lib.rs)"),
+        "stdout={stdout}"
+    );
+    for section in [
+        "Projected line reachability",
+        "Static test/benchmark reachability",
+        "Symbols",
+        "Dependencies",
+        "Dead code candidates",
+        "Call trace size",
+    ] {
+        assert!(
+            stdout.contains(section),
+            "missing section {section}: {stdout}"
+        );
+    }
+    for full_section in [
+        "ℹ Full section: cstat loc --path src/lib.rs -v",
+        "ℹ Full section: cstat test-reachability --path src/lib.rs -v",
+        "ℹ Full section: cstat symbols --path src/lib.rs -v",
+        "ℹ Full section: cstat deps --path src/lib.rs -v",
+        "ℹ Full section: cstat dead-code --path src/lib.rs -v",
+        "ℹ Full section: cstat call-trace --path src/lib.rs -v",
+    ] {
+        assert!(
+            stdout.contains(full_section),
+            "missing verbose line {full_section}: {stdout}",
+        );
+    }
+    for expected in [
+        "fn 6", "struct 1", "enum 1", "trait 1", "const 1", "static 1",
+    ] {
+        assert!(stdout.contains(expected), "missing {expected}: {stdout}");
+    }
+    assert!(stdout.contains("test/bench roots 1"), "stdout={stdout}");
+    assert!(
+        stdout.contains("not statically reachable:"),
+        "stdout={stdout}"
+    );
+    assert!(stdout.contains("orphan"), "stdout={stdout}");
+    assert!(stdout.contains("dead_child"), "stdout={stdout}");
+    assert!(stdout.contains("in-file fan-in"), "stdout={stdout}");
+    for expected in ["Call trace size", "live", "dead_parent", "orphan"] {
+        assert!(stdout.contains(expected), "missing {expected}: {stdout}");
+    }
+
+    fs::remove_dir_all(root).unwrap();
+}
+
+#[test]
+fn file_summary_json_is_untruncated_and_file_scoped() {
+    let root = temp_project("json");
+    let file = root.join("src/lib.rs");
+    let output = run_cstat(&file, &["--json", "summary"]);
+    assert_success(&output);
+
+    let stdout = String::from_utf8(output.stdout).unwrap();
+    let value: Value = serde_json::from_str(&stdout).expect("parse file summary JSON");
+    assert_eq!(value["file"], "src/lib.rs");
+    assert_eq!(value["project"], "fixture");
+    for field in [
+        "line_counts",
+        "static_reachability",
+        "symbols",
+        "dependencies",
+        "dead_code",
+        "call_trace",
+    ] {
+        assert!(value.get(field).is_some(), "missing {field}: {stdout}");
+    }
+    assert_eq!(value["symbols"]["functions"], 6);
+    assert_eq!(value["symbols"]["structs"], 1);
+    assert_eq!(value["symbols"]["enums"], 1);
+    assert_eq!(value["symbols"]["traits"], 1);
+    assert_eq!(value["symbols"]["consts"], 1);
+    assert_eq!(value["symbols"]["statics"], 1);
+    assert_eq!(
+        value["static_reachability"]["test_benchmark_entry_count"],
+        1
+    );
+    assert_json_array_contains(&value["static_reachability"]["reachable_functions"], "live");
+    assert_json_array_contains(
+        &value["static_reachability"]["reachable_functions"],
+        "helper",
+    );
+    for function in ["orphan", "dead_parent", "dead_child"] {
+        assert_json_array_contains(
+            &value["static_reachability"]["unreachable_functions"],
+            function,
+        );
+    }
+
+    let dead_code = value["dead_code"]["functions"]
+        .as_array()
+        .expect("dead code functions");
+    let dead_child = dead_code
+        .iter()
+        .find(|entry| entry["function"] == "dead_child")
+        .expect("dead_child dead-code row");
+    assert_eq!(dead_child["candidate"], true);
+    assert_eq!(dead_child["in_file_fan_in"], 1);
+    assert!(
+        dead_child["reason"]
+            .as_str()
+            .unwrap()
+            .contains("no test/benchmark root reaches that caller"),
+        "dead_child reason={:?}",
+        dead_child["reason"]
+    );
+    let orphan = dead_code
+        .iter()
+        .find(|entry| entry["function"] == "orphan")
+        .expect("orphan dead-code row");
+    assert!(
+        orphan["reason"]
+            .as_str()
+            .unwrap()
+            .contains("no direct, trait, drop, function-item, or closure edge"),
+        "orphan reason={:?}",
+        orphan["reason"]
+    );
+
+    let traces = value["call_trace"]["functions"]
+        .as_array()
+        .expect("call trace functions");
+    let live = traces
+        .iter()
+        .find(|entry| entry["function"] == "live")
+        .expect("live trace row");
+    assert!(
+        live["functions_reached"].as_u64().unwrap() > 1,
+        "live trace={live:?}",
+    );
+    let orphan = traces
+        .iter()
+        .find(|entry| entry["function"] == "orphan")
+        .expect("orphan trace row");
+    assert_eq!(orphan["functions_reached"], 1);
+
+    fs::remove_dir_all(root).unwrap();
+}
+
 #[test]
 fn file_section_commands_accept_file_path() {
     let root = temp_project("sections");
@@ -133,7 +292,7 @@ fn file_path_errors_are_clear() {
     let notes = root.join("notes.rs");
     fs::write(&notes, "fn scratch() {}\n").unwrap();
 
-    let output = run_cstat(&notes, &["loc"]);
+    let output = run_cstat(&notes, &["summary"]);
     assert!(
         !output.status.success(),
         "unexpected success: stdout={} stderr={}",
@@ -146,7 +305,7 @@ fn file_path_errors_are_clear() {
         "stderr={stderr}",
     );
 
-    let output = run_cstat(&notes, &["--json", "loc"]);
+    let output = run_cstat(&notes, &["--json", "summary"]);
     assert!(
         !output.status.success(),
         "unexpected json success: stdout={} stderr={}",

tests/scorecard_cli.rs

@@ -1,414 +0,0 @@
-use serde_json::Value;
-use std::fs;
-use std::path::{Path, PathBuf};
-use std::process::{Command, Output};
-use std::time::{SystemTime, UNIX_EPOCH};
-
-fn temp_project(name: &str) -> PathBuf {
-    let unique = SystemTime::now()
-        .duration_since(UNIX_EPOCH)
-        .unwrap()
-        .as_nanos();
-    let root = std::env::temp_dir().join(format!("cstat-scorecard-{name}-{unique}"));
-    fs::create_dir_all(root.join("src")).unwrap();
-    fs::write(
-        root.join("Cargo.toml"),
-        "[package]\nname = \"fixture\"\nversion = \"0.1.0\"\nedition = \"2021\"\n",
-    )
-    .unwrap();
-    root
-}
-
-fn run_cstat(project: &Path, args: &[&str]) -> Output {
-    let bin = env!("CARGO_BIN_EXE_cstat");
-    let mut command = Command::new(bin);
-    command.args(["--no-color", "--path"]);
-    command.arg(project);
-    command.args(args);
-    command.output().expect("invoke cstat binary")
-}
-
-fn assert_success(output: &Output) {
-    assert!(
-        output.status.success(),
-        "cstat failed: status={:?}\nstderr={}\nstdout={}",
-        output.status,
-        String::from_utf8_lossy(&output.stderr),
-        String::from_utf8_lossy(&output.stdout),
-    );
-}
-
-fn score(project: &Path) -> Value {
-    let output = run_cstat(project, &["--json", "scorecard"]);
-    assert_success(&output);
-    serde_json::from_slice(&output.stdout).expect("parse scorecard JSON")
-}
-
-fn component(value: &Value, name: &str) -> f64 {
-    value["component_costs"][name]["cost"]
-        .as_f64()
-        .unwrap_or_else(|| panic!("missing component {name}: {value}"))
-}
-
-fn total(value: &Value) -> f64 {
-    value["code_complexity_cost"]
-        .as_f64()
-        .unwrap_or_else(|| panic!("missing total: {value}"))
-}
-
-fn write_main(root: &Path, source: &str) {
-    fs::write(root.join("src/main.rs"), source).unwrap();
-}
-
-#[test]
-fn scorecard_json_contract_is_stable_and_purely_structural() {
-    let root = temp_project("json-contract");
-    fs::create_dir_all(root.join("tests")).unwrap();
-    fs::create_dir_all(root.join("benches")).unwrap();
-    write_main(
-        &root,
-        r#"fn main() {
-    live();
-}
-
-fn live() -> usize {
-    1
-}
-
-fn branchy(input: usize) -> usize {
-    let mut total = 0;
-    if input > 0 { total += 1; }
-    if input > 1 { total += 1; }
-    if input > 2 { total += 1; }
-    if input > 3 { total += 1; }
-    if input > 4 { total += 1; }
-    total
-}
-"#,
-    );
-    fs::write(
-        root.join("tests/smoke.rs"),
-        "#[test]\nfn smoke() { assert_eq!(1 + 1, 2); }\n",
-    )
-    .unwrap();
-    fs::write(root.join("benches/bench.rs"), "fn bench_helper() {}\n").unwrap();
-
-    let value = score(&root);
-    assert_eq!(value["cstat_version"], env!("CARGO_PKG_VERSION"));
-    assert_eq!(value["score_version"], "code_complexity_cost_v0");
-    for field in [
-        "target",
-        "code_complexity_cost",
-        "code_complexity_cost_per_kloc",
-        "component_costs",
-        "scope_breakdown",
-        "top_contributors",
-        "metadata",
-    ] {
-        assert!(value.get(field).is_some(), "missing {field}: {value}");
-    }
-    assert!(
-        value["component_costs"].get("verification_gap").is_none(),
-        "scorecard must not mix harness verification into code complexity: {value}",
-    );
-    for scope in ["production", "tests", "benches"] {
-        assert!(
-            value["scope_breakdown"].get(scope).is_some(),
-            "missing scope {scope}: {value}",
-        );
-    }
-    assert!(
-        value["top_contributors"]
-            .as_array()
-            .expect("top array")
-            .len()
-            <= 20,
-        "default top contributor count should be bounded: {value}",
-    );
-
-    let repeated = score(&root);
-    assert_eq!(value, repeated, "scorecard should be deterministic");
-
-    let human = run_cstat(&root, &["scorecard", "--top", "3"]);
-    assert_success(&human);
-    let stdout = String::from_utf8_lossy(&human.stdout);
-    for expected in [
-        "Code complexity score",
-        "score version: code_complexity_cost_v0",
-        "lower is cleaner; harness guards behavior separately",
-        "components:",
-        "top contributors:",
-    ] {
-        assert!(stdout.contains(expected), "missing {expected}: {stdout}");
-    }
-
-    fs::remove_dir_all(root).unwrap();
-}
-
-#[test]
-fn deliberately_messy_code_scores_worse_than_simple_code() {
-    let clean = temp_project("clean");
-    write_main(
-        &clean,
-        r#"fn main() {
-    println!("{}", live());
-}
-
-fn live() -> usize {
-    1
-}
-"#,
-    );
-
-    let messy = temp_project("messy");
-    let mut source = String::from(
-        r#"fn main() {
-    println!("{}", tangled(12));
-}
-
-fn tangled(input: usize) -> usize {
-    let mut total = 0;
-    if input > 0 { total += 1; }
-    if input > 1 { total += 1; }
-    if input > 2 { total += 1; }
-    if input > 3 { total += 1; }
-    if input > 4 { total += 1; }
-    if input > 5 { total += 1; }
-    if input > 6 { total += 1; }
-    if input > 7 {
-        if input > 8 {
-            if input > 9 {
-                total += input;
-            }
-        }
-    }
-"#,
-    );
-    for index in 0..70 {
-        source.push_str(&format!("    let value_{index} = {index};\n"));
-    }
-    source.push_str("    total\n}\n");
-    for index in 0..30 {
-        source.push_str(&format!("fn helper_{index}() -> usize {{ {index} }}\n"));
-    }
-    write_main(&messy, &source);
-
-    let clean_score = score(&clean);
-    let messy_score = score(&messy);
-    assert!(
-        total(&messy_score) > total(&clean_score),
-        "messy code should cost more: clean={clean_score} messy={messy_score}",
-    );
-    assert!(
-        component(&messy_score, "function_complexity")
-            > component(&clean_score, "function_complexity"),
-        "messy function shape should cost more: clean={clean_score} messy={messy_score}",
-    );
-    assert!(
-        component(&messy_score, "file_concentration")
-            > component(&clean_score, "file_concentration"),
-        "messy file concentration should cost more: clean={clean_score} messy={messy_score}",
-    );
-
-    fs::remove_dir_all(clean).unwrap();
-    fs::remove_dir_all(messy).unwrap();
-}
-
-#[test]
-fn adding_branching_nesting_and_large_body_does_not_reduce_function_cost() {
-    let root = temp_project("function-monotonic");
-    write_main(
-        &root,
-        r#"fn main() {
-    println!("{}", value(1));
-}
-
-fn value(input: usize) -> usize {
-    input + 1
-}
-"#,
-    );
-    let before = score(&root);
-
-    let mut source = String::from(
-        r#"fn main() {
-    println!("{}", value(1));
-}
-
-fn value(input: usize) -> usize {
-    let mut total = input;
-    if input > 0 { total += 1; }
-    if input > 1 { total += 1; }
-    if input > 2 { total += 1; }
-    if input > 3 { total += 1; }
-    if input > 4 { total += 1; }
-    if input > 5 {
-        if input > 6 {
-            if input > 7 {
-                total += input;
-            }
-        }
-    }
-"#,
-    );
-    for index in 0..80 {
-        source.push_str(&format!("    total += {index};\n"));
-    }
-    source.push_str("    total\n}\n");
-    write_main(&root, &source);
-    let after = score(&root);
-
-    assert!(
-        total(&after) > total(&before),
-        "larger, branchier body should not reduce total cost: before={before} after={after}",
-    );
-    assert!(
-        component(&after, "function_complexity") > component(&before, "function_complexity"),
-        "larger, branchier body should increase function cost: before={before} after={after}",
-    );
-    assert!(
-        component(&after, "file_concentration") >= component(&before, "file_concentration"),
-        "larger body should not reduce file concentration: before={before} after={after}",
-    );
-
-    fs::remove_dir_all(root).unwrap();
-}
-
-#[test]
-fn symbol_piles_increase_abstraction_surface_and_file_concentration() {
-    let root = temp_project("symbol-pile");
-    write_main(
-        &root,
-        r#"fn main() {
-    println!("ok");
-}
-"#,
-    );
-    let before = score(&root);
-
-    let mut source = String::from(
-        r#"fn main() {
-    println!("ok");
-}
-"#,
-    );
-    for index in 0..18 {
-        source.push_str(&format!("struct Data{index};\n"));
-    }
-    for index in 0..12 {
-        source.push_str(&format!("enum Choice{index} {{ A, B }}\n"));
-    }
-    for index in 0..30 {
-        source.push_str(&format!("fn helper_{index}() -> usize {{ {index} }}\n"));
-    }
-    write_main(&root, &source);
-    let after = score(&root);
-
-    assert!(
-        component(&after, "abstraction_surface") > component(&before, "abstraction_surface"),
-        "symbol pile should increase abstraction surface: before={before} after={after}",
-    );
-    assert!(
-        component(&after, "file_concentration") > component(&before, "file_concentration"),
-        "symbol pile should increase file concentration: before={before} after={after}",
-    );
-    assert!(
-        total(&after) > total(&before),
-        "symbol pile should increase total cost: before={before} after={after}",
-    );
-
-    fs::remove_dir_all(root).unwrap();
-}
-
-#[test]
-fn fan_out_and_bidirectional_dependencies_increase_module_coupling() {
-    let root = temp_project("coupling");
-    fs::write(root.join("src/lib.rs"), "pub mod root;\npub mod a;\n").unwrap();
-    fs::write(root.join("src/root.rs"), "pub fn touch() {}\n").unwrap();
-    fs::write(root.join("src/a.rs"), "pub fn a() {}\n").unwrap();
-    let before = score(&root);
-
-    fs::write(
-        root.join("src/lib.rs"),
-        "pub mod root;\npub mod a;\npub mod b;\npub mod c;\npub mod d;\npub mod e;\npub mod f;\n",
-    )
-    .unwrap();
-    fs::write(
-        root.join("src/root.rs"),
-        r#"use crate::a::a;
-use crate::b::b;
-use crate::c::c;
-use crate::d::d;
-use crate::e::e;
-use crate::f::f;
-
-pub fn touch() {
-    a(); b(); c(); d(); e(); f();
-}
-"#,
-    )
-    .unwrap();
-    fs::write(
-        root.join("src/a.rs"),
-        "use crate::root::touch;\npub fn a() { touch(); }\n",
-    )
-    .unwrap();
-    for module in ["b", "c", "d", "e", "f"] {
-        fs::write(
-            root.join(format!("src/{module}.rs")),
-            format!("pub fn {module}() {{}}\n"),
-        )
-        .unwrap();
-    }
-    let after = score(&root);
-
-    assert!(
-        component(&after, "module_coupling") > component(&before, "module_coupling"),
-        "fan-out and bidirectional pair should increase coupling: before={before} after={after}",
-    );
-    assert!(
-        total(&after) > total(&before),
-        "coupling fixture should increase total cost: before={before} after={after}",
-    );
-
-    fs::remove_dir_all(root).unwrap();
-}
-
-#[test]
-fn adding_static_dead_code_candidate_increases_stale_surface() {
-    let root = temp_project("stale");
-    write_main(
-        &root,
-        r#"fn main() {
-    live();
-}
-
-fn live() {}
-"#,
-    );
-    let before = score(&root);
-
-    write_main(
-        &root,
-        r#"fn main() {
-    live();
-}
-
-fn live() {}
-
-fn unused_candidate() {}
-"#,
-    );
-    let after = score(&root);
-
-    assert!(
-        component(&after, "stale_surface") > component(&before, "stale_surface"),
-        "unused private function should increase stale surface: before={before} after={after}",
-    );
-    assert!(
-        total(&after) > total(&before),
-        "unused private function should increase total cost: before={before} after={after}",
-    );
-
-    fs::remove_dir_all(root).unwrap();
-}

tests/test_reachability_cli.rs

@@ -188,21 +188,21 @@ fn test_reachability_json_uses_reachability_fields() {
 }
 
 #[test]
-fn stale_summary_report_and_advanced_commands_are_unavailable() {
-    let root = temp_project("stale-commands");
+fn focused_report_json_renames_top_level_field() {
+    let root = temp_project("report-json");
+    let output = run_cstat(&root, &["--json", "report"]);
+    assert_success(&output);
 
-    for args in [
-        &["summary"][..],
-        &["report"][..],
-        &["advanced"][..],
-        &["advanced", "flow-heatmap", "--walks", "10"][..],
-    ] {
-        let output = run_cstat(&root, args);
+    let stdout = String::from_utf8(output.stdout).unwrap();
+    let value: Value = serde_json::from_str(&stdout).expect("parse focused report JSON");
+    assert!(value.get("test_reachability").is_some());
+    assert!(value.get("datapaths").is_none());
+    assert_eq!(value["test_reachability"]["reachable_function_count"], 3);
+    assert_eq!(value["test_reachability"]["unreachable_function_count"], 1);
+    for field in ["line_counts", "symbols", "dependencies", "dead_code"] {
         assert!(
-            !output.status.success(),
-            "stale command unexpectedly succeeded for {args:?}: stdout={} stderr={}",
-            String::from_utf8_lossy(&output.stdout),
-            String::from_utf8_lossy(&output.stderr),
+            value.get(field).is_some(),
+            "missing focused report field: {field}"
         );
     }
 
@@ -210,7 +210,52 @@ fn stale_summary_report_and_advanced_commands_are_unavailable() {
 }
 
 #[test]
-fn help_lists_focused_commands_and_omits_pruned_commands() {
+fn advanced_flow_heatmap_runs_legacy_random_walk_analysis() {
+    let root = temp_project("advanced");
+    let output = run_cstat(&root, &["advanced", "flow-heatmap", "--walks", "10"]);
+    assert_success(&output);
+
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    assert!(stdout.contains("Execution Flow Heatmap"), "stdout={stdout}");
+    assert!(stdout.contains("random walks"), "stdout={stdout}");
+    assert!(
+        !stdout.contains("Static test/benchmark reachability"),
+        "stdout={stdout}"
+    );
+
+    fs::remove_dir_all(root).unwrap();
+}
+
+#[test]
+fn old_focused_datapaths_command_is_not_available() {
+    let root = temp_project("old-command");
+    let output = run_cstat(&root, &["datapaths"]);
+    assert!(
+        !output.status.success(),
+        "legacy root command unexpectedly succeeded: stdout={} stderr={}",
+        String::from_utf8_lossy(&output.stdout),
+        String::from_utf8_lossy(&output.stderr),
+    );
+
+    fs::remove_dir_all(root).unwrap();
+}
+
+#[test]
+fn old_advanced_datapaths_command_is_not_available() {
+    let root = temp_project("old-advanced-command");
+    let output = run_cstat(&root, &["advanced", "datapaths"]);
+    assert!(
+        !output.status.success(),
+        "legacy advanced command unexpectedly succeeded: stdout={} stderr={}",
+        String::from_utf8_lossy(&output.stdout),
+        String::from_utf8_lossy(&output.stderr),
+    );
+
+    fs::remove_dir_all(root).unwrap();
+}
+
+#[test]
+fn help_lists_test_reachability_and_advanced_flow_heatmap() {
     let root = temp_project("help");
 
     let root_help = run_cstat(&root, &["--help"]);
@@ -224,14 +269,30 @@ fn help_lists_focused_commands_and_omits_pruned_commands() {
         root_stdout.contains("Static test/benchmark reachability"),
         "stdout={root_stdout}"
     );
-    for pruned in ["summary", "report", "advanced", "datapaths"] {
-        assert!(
-            !root_stdout
-                .lines()
-                .any(|line| line.trim_start().starts_with(pruned)),
-            "help still listed pruned command {pruned}: {root_stdout}"
-        );
-    }
+    assert!(
+        !root_stdout
+            .lines()
+            .any(|line| line.starts_with("  datapaths")),
+        "root help still listed datapaths: {root_stdout}"
+    );
+
+    let advanced_help = run_cstat(&root, &["advanced", "--help"]);
+    assert_success(&advanced_help);
+    let advanced_stdout = String::from_utf8_lossy(&advanced_help.stdout);
+    assert!(
+        advanced_stdout.contains("flow-heatmap"),
+        "stdout={advanced_stdout}"
+    );
+    assert!(
+        !advanced_stdout
+            .lines()
+            .any(|line| line.starts_with("  datapaths")),
+        "advanced help still listed datapaths: {advanced_stdout}"
+    );
+    assert!(
+        advanced_stdout.contains("random-walk") || advanced_stdout.contains("heatmap"),
+        "stdout={advanced_stdout}"
+    );
 
     fs::remove_dir_all(root).unwrap();
 }