KBeaconProvisioner had no onStatusUpdate callback, so the UI showed a static
"Connecting..." message during the entire auth cycle (5 passwords × 5s timeout
× 3 retries = 75s of dead silence). Now reports each phase: connecting,
discovering services, authenticating (with password attempt count), writing,
saving.
Also fixed ScanView disconnect handler to cover .writing and .verifying states —
previously only handled .connecting/.connected, so a mid-write disconnect left
the UI permanently stuck.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>