* fix: project label text hidden by selection overlay in dark mode
In NavRail's ProjectTile, the expanded active item renders an absolutely
positioned background overlay (--interactive-selection) that visually
covers the text label. The label span was missing 'relative z-10',
unlike NavRailActionButton which correctly uses it.
Fixes text being invisible on selected project in dark themes
(nord-dark, dracula-dark, monokai-dark, gruvbox-dark, etc.)
* feat: auto-save file editor with 1.5s debounce
Add debounced auto-save to the file editor so users no longer need to
manually save with Cmd/Ctrl+S or the save button. Files are automatically
saved 1.5 seconds after the user stops typing.
- Debounced auto-save effect that triggers on draft content changes
- Cmd/Ctrl+S still works for immediate save (cancels pending debounce)
- Updated save button UI with contextual status indicators:
'Saving...' spinner, 'Saved' checkmark, or save icon when dirty
- Reset auto-save status when switching between files
- Applied consistently to both normal and fullscreen editor views
Nguyễn Ngô Thượng
e57f17996f