Phase 1+2 구현: Electron 뼈대 + STT/핫키/오케스트레이터

Phase 1:
- 프로젝트 초기화 (TypeScript strict, electron-vite, ESLint, Prettier)
- shared 타입 (ipc-channels 113채널, types, errors, constants)
- 메인 프로세스 뼈대 (bootstrap, lifecycle, 단일 인스턴스)
- LoggerService, ConfigService (electron-store ESM dynamic import)
- React 19 + MUI 7 Dashboard, 시스템 트레이

Phase 2:
- AudioCaptureService (node-record-lpcm16, PCM16 16kHz mono)
- HotkeyService (uiohook-napi, 더블프레스, holdMode/toggleMode)
- LocalSTTService (faster-whisper Python sidecar, 이중 조건 플러시)
- VoiceModeService 오케스트레이터 (이중 상태머신, Action Queue)
- Python sidecar (FastAPI: health/load/transcribe/shutdown)
- IPC 핸들러 (voice, stt, hotkey) + Preload API 확장

src/main/types/node-record-lpcm16.d.ts

@@ -0,0 +1,33 @@
+// Type declarations for node-record-lpcm16 (no @types package available)
+
+declare module 'node-record-lpcm16' {
+  import { ChildProcess } from 'child_process'
+  import { Readable } from 'stream'
+
+  interface RecordingOptions {
+    sampleRate?: number
+    channels?: number
+    compress?: boolean
+    threshold?: number
+    thresholdStart?: number | null
+    thresholdEnd?: number | null
+    silence?: string
+    recorder?: 'sox' | 'rec' | 'arecord'
+    endOnSilence?: boolean
+    audioType?: string
+    device?: string
+  }
+
+  interface Recording {
+    process: ChildProcess
+    stop(): void
+    pause(): void
+    resume(): void
+    isPaused(): boolean
+    stream(): Readable
+  }
+
+  function record(options?: RecordingOptions): Recording
+
+  export { record, Recording, RecordingOptions }
+}