Deadlock and lock ordering

Capture goroutine stacks and look for common waits: a mutex held across I/O, a full channel with no consumer, a WaitGroup whose owner waits before starting the receiver, or a cyclic lock acquisition.

Use a consistent global lock order when two locks are unavoidable. Shrink critical sections and avoid callbacks under locks because callbacks can reenter code or acquire locks in unknown order.

A partial deadlock may not trigger the runtime all-goroutines-asleep panic while timers or background goroutines continue. Expose queue progress and dependency health, not just process liveness.