This milestone implements comprehensive remote synchronization capabilities
and authentication support for Onyx, completing the core workflow features.
## Rebase Engine (internal/git/rebase.go)
- Stacked rebase with sequential commit processing
- Conflict detection and handling
- Integration with rerere for automatic conflict resolution
- Support for rebase continuation and abort operations
## Rerere Integration (internal/git/rerere.go)
- Conflict resolution recording and replay
- Cache location: .onx/rerere_cache
- Automatic application of previous conflict resolutions
- SHA1-based conflict pattern matching with normalization
## Conflict Resolution UI (internal/git/conflicts.go)
- Index-based conflict detection using Git stages (1/2/3)
- Clear conflict presentation with file paths and commit hashes
- User-friendly resolution guidance
- Conflict marker extraction and analysis
## Remote Commands
### onx sync (internal/commands/sync.go)
- Fetch latest changes from remote origin
- Rebase workstream stack onto updated base branch
- Automatic rerere conflict resolution
- Transaction-wrapped with full undo support
- Comprehensive progress reporting and error messages
### onx push (internal/commands/push.go)
- Push all workstream branches to remote
- Support for force push operations
- Per-branch progress reporting
- Clear summary of pushed branches
- Push workstream commits to refs/heads/onyx/workstreams/...
## Authentication (internal/git/auth.go)
- Multi-method authentication with auto-detection
- SSH: ssh-agent and ~/.ssh key file support
- HTTPS: git credential helper and environment variables
- Credential caching for performance
- Graceful fallback when authentication unavailable
## Remote Helpers (internal/git/remote.go)
- Remote validation and configuration
- Support for multiple remotes with origin as default
- URL retrieval and remote existence checking
## Dogfooding
- Updated CLAUDE.md with mandatory Onyx-only development policy
- All future development (human and AI) must use Onyx commands
- Exceptions documented for git usage (remotes, PRs, debugging)
## Status
✅ All Milestone 4 features implemented and tested
✅ Successfully used Onyx for its own development
✅ Authentication working with remote repositories
✅ Full stacked-diff workflow operational