## Milestone 4: Synchronization and Remote Interaction ✓ COMPLETE

### Rebase Engine ✓

34. **Implement stacked rebase** (`internal/git/rebase.go`) ✓
    - Implemented RebaseStack function
    - Sequential rebase with conflict handling
    - Integration with rerere for automatic conflict resolution
    - Support for rebase continuation and abort

35. **Integrate rerere** (`internal/git/rerere.go`) ✓
    - Configured rerere cache location (.onx/rerere_cache)
    - Enabled rerere for rebase operations
    - Implemented conflict detection and recording
    - Apply recorded resolutions automatically

36. **Create conflict resolution UI** (`internal/git/conflicts.go`) ✓
    - Detect merge conflicts via index stages
    - Present clear conflict markers with file paths
    - Guide user through resolution process
    - Record resolutions for rerere

### Sync and Push Commands ✓

37. **Implement onx sync** (`internal/commands/sync.go`) ✓
    - Begin oplog transaction for undo support
    - Fetch from remote (origin by default)
    - Get workstream commit stack
    - Sequential rebase with rerere support
    - Handle and present conflicts clearly
    - Update workstreams.json with new SHAs
    - Finalize oplog transaction

38. **Implement onx push** (`internal/commands/push.go`) ✓
    - Get all branches in current workstream
    - Push each workstream branch to remote
    - Support for force push flag
    - Progress reporting for each branch
    - Clear summary of pushed branches

39. **Add remote configuration** (`internal/git/remote.go`) ✓
    - Read git remote configuration
    - Support multiple remotes
    - Default to "origin"
    - Validate remote existence and URLs