1. Replace if/elif dispatch chain with _DISPATCH dict (engines/node.py)
   Adding a proto message kind now requires exactly one entry in _DISPATCH —
   impossible to add a callback slot without the routing case. Missing kinds
   emit WARNING immediately. Extractor is colocated with the route so the
   wrong-object bug (Bug 1) cannot recur.

2. Honour CORTEX_DISABLE_AUTO_UPDATE env var (updater.py)
   In Docker, updates are delivered via image rebuilds. The old behaviour
   called sys.exit(0) to spawn a bootstrapper, which Docker restart:always
   turned into an infinite boot loop. Setting CORTEX_DISABLE_AUTO_UPDATE=1
   in the container env prevents this entirely.

3. Watchdog ticks unconditionally in health reporter (node.py)
   Previously the watchdog tick was skipped when the hub was unreachable,
   causing os._exit(1) after 300s of any disconnect — even during normal
   gRPC reconnect backoff. Now the watchdog proves the reporter thread is
   alive regardless of hub state; it only fires if the thread itself deadlocks.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>