Add automated detection of 6 runtime anomaly types with severity levels:
- PoisonedActor (critical): actor panicked
- StalledActor (high): no message processing while mailbox > 0
- GrowingMailbox (medium): consecutive increases in mailbox depth
- MailboxOverflow (medium): messages dropped (backpressure triggered)
- WorkerImbalance (low): one worker has >2x average actor count
- EmptyWorker (low): worker has 0 actors while others have many
Configurable thresholds with sensible defaults. 7 scenario tests covering
all warning types, threshold behavior, and streak reset logic.
Web: warning banner at top of overview page with severity-colored alerts
TUI: warning count in summary bar (yellow when active)
SSE: new "warnings" event sent with each stats tick
Authored by Claude, lovingly guided by Zachery Aaron Shores-Chmielewski
70555c2daf