refactor: deduplicate message routing pattern in tick_once

Extract route_to_pool_or_remote() helper that unifies the routing
logic (local pool → address_map → inbox_registry) used in phases
2.5 (worker extension delivery) and 7 (death notifications).

Completes P0 core debloating: 2636→2319 (−317, −12.0%).
worker.rs: 845→598 (−247, −29.2%).

Authored by Claude, lovingly guided by Zachery Aaron Shores-Chmielewski

src/worker.rs

@@ -15,6 +15,29 @@ use crate::Error;
 
 use crate::extension::WorkerExtension;
 
+/// Route a message: try local pool first, then address_map for cross-worker,
+/// then inbox_registry for external receivers.
+fn route_to_pool_or_remote(
+    pool: &mut ActorPool,
+    tc: &TickContext,
+    dest: ActorAddress,
+    msg: Box<dyn Any + Send>,
+) {
+    if pool.contains(&dest) {
+        pool.deliver(&dest, msg);
+    } else {
+        match tc.address_map.lookup(&dest) {
+            Some(wid) => {
+                tc.transfer_txs[wid.as_usize()].send(Envelope::new(dest, msg));
+                crate::runtime::notify_worker(tc.worker_threads, wid.as_usize());
+            }
+            None => {
+                let _ = tc.inbox_registry.try_deliver(dest, msg);
+            }
+        }
+    }
+}
+
 // ─── Worker ─────────────────────────────────────────────────────────────────
 
 /// A worker owns a set of actors and runs them in a loop.
@@ -83,23 +106,12 @@ impl Worker {
         let t2 = Instant::now();
 
         // 2.5. Fire per-worker extension (e.g., timers) → deliver before tick_all
-        if let Some(ext) = &mut self.worker_ext {
+        let ext_msgs: Vec<_> = self.worker_ext.as_mut()
-            for (dest, msg) in ext.on_tick() {
+            .map(|ext| ext.on_tick())
-                if self.pool.contains(&dest) {
+            .unwrap_or_default();
-                    self.pool.deliver(&dest, msg);
+        for (dest, msg) in ext_msgs {
-                } else {
+            route_to_pool_or_remote(&mut self.pool, tc, dest, msg);
-                    match tc.address_map.lookup(&dest) {
+            did_work = true;
-                        Some(wid) => {
-                            tc.transfer_txs[wid.as_usize()].send(Envelope::new(dest, msg));
-                            crate::runtime::notify_worker(tc.worker_threads, wid.as_usize());
-                        }
-                        None => {
-                            let _ = tc.inbox_registry.try_deliver(dest, msg);
-                        }
-                    }
-                }
-                did_work = true;
-            }
         }
 
         // 3. Tick all actors with WorkerContext
@@ -233,22 +245,9 @@ impl Worker {
                     let dead_addrs: Vec<_> = dead.iter().map(|(a, _)| *a).collect();
                     ext.cleanup_dead(&dead_addrs);
 
-                    // Deliver Down notifications through normal routing
+                    // Deliver death notifications through normal routing
                     for (dest, msg) in notifications {
-                        if self.pool.contains(&dest) {
+                        route_to_pool_or_remote(&mut self.pool, tc, dest, msg);
-                            self.pool.deliver(&dest, msg);
-                        } else {
-                            match tc.address_map.lookup(&dest) {
-                                Some(wid) => {
-                                    tc.transfer_txs[wid.as_usize()]
-                                        .send(Envelope::new(dest, msg));
-                                    crate::runtime::notify_worker(tc.worker_threads, wid.as_usize());
-                                }
-                                None => {
-                                    let _ = tc.inbox_registry.try_deliver(dest, msg);
-                                }
-                            }
-                        }
                     }
                 }