- Added 'opal sync merge' command for initial database merge
- Support for merge strategies: prefer-local, prefer-server, smart (default)
- Offline queue already implemented in Phase 2
- Conflict warning display already implemented in Phase 2-3
- Full offline mode support with automatic queueing when server unreachable
- Created comprehensive sync command suite:
- 'opal sync init' - Configure sync with server (URL, API key)
- 'opal sync status' - Show sync configuration and queue status
- 'opal sync now' - Bidirectional sync with conflict resolution
- 'opal sync up' - Push local changes to server
- 'opal sync down' - Pull server changes to local
- 'opal sync log' - View conflict resolution log
- Added interactive prompts for init (URL and API key)
- Automatic client ID generation (UUID)
- Display user-friendly sync results with emojis
- Support for viewing queued offline changes
- Integration with config system for persistent sync settings