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/store/authStore.ts

@@ -25,6 +25,8 @@ interface AuthState {
   scrobblingEnabled: boolean;
   maxCacheMb: number;
   downloadFolder: string;
+  excludeAudiobooks: boolean;
+  customGenreBlacklist: string[];
 
   // Status
   isLoggedIn: boolean;
@@ -44,6 +46,8 @@ interface AuthState {
   setScrobblingEnabled: (v: boolean) => void;
   setMaxCacheMb: (v: number) => void;
   setDownloadFolder: (v: string) => void;
+  setExcludeAudiobooks: (v: boolean) => void;
+  setCustomGenreBlacklist: (v: string[]) => void;
   logout: () => void;
 
   // Derived
@@ -68,6 +72,8 @@ export const useAuthStore = create<AuthState>()(
       scrobblingEnabled: true,
       maxCacheMb: 500,
       downloadFolder: '',
+      excludeAudiobooks: false,
+      customGenreBlacklist: [],
       isLoggedIn: false,
       isConnecting: false,
       connectionError: null,
@@ -109,6 +115,8 @@ export const useAuthStore = create<AuthState>()(
       setScrobblingEnabled: (v) => set({ scrobblingEnabled: v }),
       setMaxCacheMb: (v) => set({ maxCacheMb: v }),
       setDownloadFolder: (v) => set({ downloadFolder: v }),
+      setExcludeAudiobooks: (v) => set({ excludeAudiobooks: v }),
+      setCustomGenreBlacklist: (v) => set({ customGenreBlacklist: v }),
 
       logout: () => set({ isLoggedIn: false }),