- Add workspace file APIs and hooks for session-scoped file browsing
- Create WorkspaceSelector component for switching between workspaces
- Update FileBrowserModal with workspace mode and improved UX
- Add files button to header with workspace-aware file browsing
- Add session files indicator to task cards for quick file access
- Include comprehensive tests for all new components and hooks
- Add mobile view state and screen size detection in FileBrowserModal
- Add back button and conditional layout with CSS classes for mobile/desktop
- Add mobile CSS for two-state layout (file list and editor views)
- Add comprehensive tests for mobile view interactions and navigation
- Add changeset for release notes
