When UpdateService encounters bind address conflicts (port already in use),
the handler now automatically deletes existing forward services and retries
the AddService operation. This resolves issues where a forward's own stale
listener prevents the update.
- Add isBindAddressInUseError() to detect port bind conflicts
- Add rebindForwardServiceOnSelfOccupiedPort() for automatic cleanup and retry
- Add HasOtherForwardOnNodePort() repository method to verify port ownership
- Add unit tests for bind conflict detection
- Pass connectIp through resolveChainProbeTarget in diagnosis stream start items
- Pass connectIp in appendChainHopDiagnosis for full chain probes
- Reconstruct tunnel state with connectIp field preserved
- Fix forward service config when bindIP already contains port
- Add contract tests for connectIp diagnosis scenarios
- Add unit test for bindIP with port in buildForwardServiceConfigs
- Update AGENTS.md with plan document rules
Entire-Checkpoint: 35a2e61c2431
* feat: add comprehensive migration test for legacy columns
- Add ExtraIPs, TCPListenAddr, UDPListenAddr to Node migration
- Add ip_preference to Tunnel migration
- Add test for very legacy database migration (1.x schema)
- Include issue #211 tracking document
Entire-Checkpoint: 0d086883c34a
* fix: apply custom IP binding to forward and tunnel chain services
Entire-Checkpoint: ceff329d4cf4
sagitchu