feat: local offline voice models (sherpa-onnx) with model manager and wake word (v2.1.0)

- electron/voice: model catalog (Whisper base/small/turbo, SenseVoice, Kokoro v1.0,
  Piper fr), streaming tar.bz2 downloader with progress, sherpa-onnx worker running in
  an Electron utilityProcess (transcribe / synthesize / status / unload), IPC + bridge.
- Renderer: 'local' providers for STT and TTS, Settings → Modèles locaux (download,
  progress, delete, activate), speaker selection, hands-free wake word with a tolerant
  matcher (accents, punctuation, edit distance) and attention window after a bare wake word.
- Packaging: native addon and worker unpacked from the asar; release 2.1.0.

Validated on Linux: Kokoro (fr) → Whisper base round trip, Piper (fr) → Whisper round trip.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017Wn5VX9HNbJ7N54hR24u9Y

src/App.tsx

@@ -10,6 +10,7 @@ import { useChat } from './state/chat';
 import { useHermes } from './state/hermes';
 import { useSettings } from './state/settings';
 import { useVoice } from './state/voice';
+import { useVoiceModels } from './state/voiceModels';
 import { ChatPanel } from './components/chat/ChatPanel';
 import { PendingRequests } from './components/chat/PendingRequests';
 import { CompactWidget } from './components/compact/CompactWidget';
@@ -41,6 +42,8 @@ function useBoot(): boolean {
         Log.error('app', 'window.eveflow missing inside Electron');
       }
       if (api) {
+        disposers.push(useVoiceModels.getState().subscribe());
+        void useVoiceModels.getState().refresh();
         disposers.push(api.hermes.onPush(handlePush));
         disposers.push(
           api.hotkeys.on((event) => {