feat: Rust audio engine, genre mix, queue shuffle, and UX improvements (v1.2.0)

### Audio Engine
- Replace Howler.js with native Rust/rodio backend (src-tauri/src/audio.rs)
- audio_play/pause/resume/stop/seek/set_volume Tauri commands
- Generation counter cancels stale in-flight downloads on skip
- Wall-clock position tracking; audio:ended after 2 ticks near end

### Playback Persistence
- Persist currentTrack, queue, queueIndex, currentTime to localStorage
- Cold-start resume: play + seek to saved position on app restart
- Position priority: server queue > localStorage

### Random Mix
- Genre blacklist: excludeAudiobooks toggle + custom chip-based blacklist
- Clickable genre chips in tracklist to blacklist on the fly
- Super Genre Mix: 9 genres, progressive rendering, Load 10 more
- Promise.allSettled + 45s timeout for large Metal/Rock libraries
- Two-column filter panel at top of page

### Queue & UI
- Shuffle button in queue header (Fisher-Yates, keeps current track at 0)
- LiveSearch arrow key / Enter / Escape keyboard navigation
- Multi-line tooltip support (data-tooltip-wrap attribute)
- Update link uses Tauri shell open() to launch system browser
- Sidebar min-width 180px → 200px (fixes Psysonic title clipping)
- Tooltip z-index fix: main-content z-index:1 over queue panel

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/api/subsonic.ts

@@ -74,6 +74,8 @@ export interface SubsonicSong {
   samplingRate?: number;
   channelCount?: number;
   starred?: string;
+  genre?: string;
+  path?: string;
 }
 
 export interface SubsonicPlaylist {
@@ -160,8 +162,10 @@ export async function getAlbumList(
   return data.albumList2?.album ?? [];
 }
 
-export async function getRandomSongs(size = 50): Promise<SubsonicSong[]> {
-  const data = await api<{ randomSongs: { song: SubsonicSong[] } }>('getRandomSongs.view', { size });
+export async function getRandomSongs(size = 50, genre?: string, timeout = 15000): Promise<SubsonicSong[]> {
+  const params: Record<string, string | number> = { size };
+  if (genre) params.genre = genre;
+  const data = await api<{ randomSongs: { song: SubsonicSong[] } }>('getRandomSongs.view', params, timeout);
   return data.randomSongs?.song ?? [];
 }