The merger was using `git diff HEAD..branch --stat` which includes
artifacts from other tasks when branches fork from older main commits.
Switch to `git diff $(merge-base)..branch --stat` so commit messages
only describe the branch's own changes.
Also surface the "files changed" button on done task cards using
mergeDetails, opening the same ChangedFilesModal with commit-backed
diffs (matching the Changes tab in the task modal).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- Redesign ChangedFilesModal as a two-view navigation flow (file list → file detail) with back navigation
- Fix theming and loading/reading ergonomics for the diff viewer
- Enhance useChangedFiles hook with improved loading and error states
- Add comprehensive tests for modal navigation, diff rendering, and edge cases
- Update styles with mobile-friendly layout and diff viewer improvements
- Update dashboard README with mobile navigation description
- Add backend API endpoint to get changed files and diffs for a task worktree
- Add useChangedFiles hook for fetching and managing diff data
- Create ChangedFilesModal component with file list and diff viewer
- Integrate modal into TaskCard with click handler to view changes
- Add frontend API integration and type definitions
- Include unit tests for hook and modal components
- Add changeset for the new feature
- Remove deprecated mission-related test files
