Add ConvoyWatcher that monitors bd activity for issue closes and
triggers convoy completion checks immediately rather than waiting
for patrol.
- Watch bd activity --follow --town --json for status=closed events
- Query SQLite for convoys tracking the closed issue
- Trigger gt convoy check when tracked issue closes
- Convoys close within seconds of last issue closing
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
