- Add modifiedFiles and baseCommitSha tracking during task execution
- Create GET /tasks/:id/diff API endpoint for file list and patches
- Build TaskChangesTab component with expandable file diffs
- Integrate Changes tab into TaskDetailModal for in-progress, in-review, and done tasks
- Add database columns and types for diff tracking
- Update executor to capture modified files during agent sessions
- Import getDefaultProject from project-context.js instead of duplicating
- Remove local getDefaultProject implementation in project.ts
- All 6 tests still passing
