Auto-recovery when broker loses registration state

[ArchieIndian]

When the broker restarts and loses state, workers get "not registered" errors and die. Instead of dying, workers should auto-recover.

Flow:

1. Worker gets 403 "not registered"
2. Loads email from saved config
3. Calls POST /recover with name + email
4. Calls POST /reset-secret with the token
5. Updates local config with new secret
6. Retries registration

If no email on file, log clear instructions for manual re-registration.

Reference

See old_mvp/km/worker/src/fabric.rs (attempt_recovery_and_reregister).