- Deleted apps/web/src/utils/optimisticStoreUpdates.ts (unused file)
- File was unused - no imports found in codebase
- Mutations already use React Query's onMutate pattern
- No TypeScript errors after deletion
- Actions 4.4.1.2 and 4.4.1.3 complete
- Completed Action 1.4.1.1: Added X-API-Version header to all requests
- Completed Action 1.4.1.4: Added API_VERSION to env config (defaults to 'v1')
- Header added in request interceptor before other headers
- Version configurable via VITE_API_VERSION environment variable
- Removed requireFeature guards from collaborator functions
- Updated addCollaborator to use unwrapped response format
- Implemented getCollaborators to call GET endpoint
- Enabled PLAYLIST_COLLABORATION feature flag
- All collaborator CRUD operations now functional
Phase: PHASE-1
Priority: P0
Progress: 10/267 (3.7%)