Cross-platform distribution, UI improvements, and performance optimizations

- PyInstaller frozen sidecar: spec file, build script, and ffmpeg path resolver
  for self-contained distribution without Python prerequisites
- Dual-mode sidecar launcher: frozen binary (production) with dev mode fallback
- Parallel transcription + diarization pipeline (~30-40% faster)
- GPU auto-detection for diarization (CUDA when available)
- Async run_pipeline command for real-time progress event delivery
- Web Audio API backend for instant playback and seeking
- OpenAI-compatible provider replacing LiteLLM client-side routing
- Cross-platform RAM detection (Linux/macOS/Windows)
- Settings: speaker count hint, token reveal toggles, dark dropdown styling
- Loading splash screen, flexbox layout fix for viewport overflow
- Gitea Actions CI/CD pipeline (Linux, Windows, macOS ARM)
- Updated README and CLAUDE.md documentation

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/lib/components/WaveformPlayer.svelte

@@ -13,6 +13,7 @@
   let container: HTMLDivElement;
   let wavesurfer: WaveSurfer | null = $state(null);
   let isReady = $state(false);
+  let isLoading = $state(false);
   let currentTime = $state('0:00');
   let totalTime = $state('0:00');
 
@@ -32,6 +33,7 @@
       barWidth: 2,
       barGap: 1,
       barRadius: 2,
+      backend: 'WebAudio',
     });
 
     wavesurfer.on('timeupdate', (time: number) => {
@@ -41,6 +43,7 @@
 
     wavesurfer.on('ready', () => {
       isReady = true;
+      isLoading = false;
       const dur = wavesurfer!.getDuration();
       durationMs.set(Math.round(dur * 1000));
       totalTime = formatTime(dur);
@@ -55,7 +58,7 @@
     });
 
     if (audioUrl) {
-      wavesurfer.load(audioUrl);
+      loadAudio(audioUrl);
     }
   });
 
@@ -89,16 +92,13 @@
       console.warn('[voice-to-notes] seekTo ignored — audio not ready yet');
       return;
     }
-    const timeSec = timeMs / 1000;
-    wavesurfer.setTime(timeSec);
-    if (!wavesurfer.isPlaying()) {
-      wavesurfer.play();
-    }
+    wavesurfer.setTime(timeMs / 1000);
   }
 
   /** Load a new audio file. */
   export function loadAudio(url: string) {
     isReady = false;
+    isLoading = true;
     wavesurfer?.load(url);
   }
 </script>