Phase 4: i18n all 15 components from PR #19. Sidebar gains collapse/expand
toggle. Player gets playback speed selector (0.25x-2.0x) fixing bug B1
(hardcoded Chinese '正常'). SongList adds inline title editing and model
version badge. Delete actions now use ConfirmDialog instead of
window.confirm. Volume persisted to localStorage. Training nav item
deferred to Phase 7.
- Player: Show minimal placeholder when no song is playing instead of hiding
- RightSidebar: Add play button overlay on cover art thumbnail
- Hover to reveal play/pause button
- Click anywhere on cover to play
- Shows pause icon when song is currently playing
- SettingsModal: Add GitHub repo link for issues and feature requests
fspecii