chore: Archive all pending OpenSpec proposals

Force archive the following proposals:
- add-audio-device-selector (complete)
- add-embedded-backend-packaging (19/26 tasks)
- add-flexible-deployment-options (20/21 tasks)

New specs created:
- audio-device-management (7 requirements)
- embedded-backend (8 requirements)

Updated specs:
- transcription (+2 requirements for model download progress)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

openspec/changes/archive/2025-12-22-add-embedded-backend-packaging/design.md

@@ -0,0 +1,115 @@
+# Design: Embedded Backend Packaging
+
+## Context
+Meeting Assistant uses a three-tier architecture: Electron Client → FastAPI Middleware → MySQL/Dify. For enterprise deployment, administrators want to distribute a single executable that users can run without additional setup. The backend must still connect to remote MySQL and Dify services (no local database).
+
+**Stakeholders:**
+- Enterprise IT administrators (simplified deployment)
+- End users (double-click to run)
+- Developers (maintain backward compatibility)
+
+## Goals / Non-Goals
+
+### Goals
+- Package backend as a sidecar executable using PyInstaller
+- Electron manages backend lifecycle (start on launch, stop on close)
+- Single `config.json` for all configuration (frontend, backend, whisper)
+- Health check ensures backend is ready before showing UI
+- Backward compatible with existing separate-deployment mode
+- Show Whisper model download progress to improve UX
+
+### Non-Goals
+- Embedding MySQL database (still remote)
+- Embedding LLM model (still uses Dify API)
+- Removing external authentication (still requires company SSO)
+- Pre-bundling Whisper model (user downloads on first run)
+
+## Decisions
+
+### Decision 1: Use PyInstaller for Backend Packaging
+**What:** Package FastAPI + uvicorn as standalone executable using PyInstaller `--onedir` mode.
+
+**Why:**
+- Consistent with existing transcriber sidecar approach
+- `--onedir` provides faster startup than `--onefile`
+- Team already has PyInstaller expertise
+
+**Alternatives considered:**
+- Nuitka: Better optimization but longer build times
+- cx_Freeze: Less community support for FastAPI
+
+### Decision 2: Configuration via Extended config.json
+**What:** Add `backend` section to existing `config.json` with database, API, and auth settings.
+
+**Why:**
+- Single configuration file for users to manage
+- Runtime modifiable without rebuilding
+- Consistent with existing whisper config pattern
+
+**Schema:**
+```json
+{
+  "apiBaseUrl": "http://localhost:8000/api",
+  "backend": {
+    "embedded": true,
+    "host": "127.0.0.1",
+    "port": 8000,
+    "database": { "host": "", "port": 33306, "user": "", "password": "", "database": "" },
+    "externalApis": { "authApiUrl": "", "difyApiUrl": "", "difyApiKey": "", "difySttApiKey": "" },
+    "auth": { "adminEmail": "", "jwtSecret": "", "jwtExpireHours": 24 }
+  }
+}
+```
+
+### Decision 3: Health Check Before Window Display
+**What:** Electron polls `/api/health` endpoint before creating main window.
+
+**Why:**
+- Prevents "connection refused" errors on startup
+- Provides clear feedback if backend fails to start
+- Maximum 30 attempts with 1-second intervals
+
+### Decision 4: Backward Compatibility via Feature Flag
+**What:** `backend.embedded: false` (default) preserves existing behavior; `true` enables embedded mode.
+
+**Why:**
+- Existing deployments continue working unchanged
+- Gradual migration path for enterprises
+- Same codebase supports both deployment models
+
+### Decision 5: Huggingface Hub Progress Callback for Model Download
+**What:** Intercept huggingface_hub download progress and emit JSON status messages.
+
+**Why:**
+- faster-whisper uses huggingface_hub internally
+- Can emit progress without modifying faster-whisper source
+- JSON format consistent with existing sidecar protocol
+
+## Risks / Trade-offs
+
+| Risk | Impact | Mitigation |
+|------|--------|------------|
+| PyInstaller hidden imports missing | Backend fails to start | Comprehensive hidden-import list; test on clean Windows |
+| Config file contains sensitive data | Security exposure | Document security best practices; consider encryption |
+| Backend startup timeout | Poor UX | Increase timeout; show loading indicator |
+| Port 8000 already in use | Backend fails | Allow configurable port; detect and report conflicts |
+
+## Migration Plan
+
+### For New Deployments (All-in-One)
+1. Build with `--embedded-backend` flag
+2. Configure `config.json` with database/API credentials
+3. Distribute single exe to users
+
+### For Existing Deployments (Separate Backend)
+1. No changes required
+2. Ensure `backend.embedded: false` in config
+3. Continue using existing backend deployment
+
+### Rollback
+- Set `backend.embedded: false` to disable embedded backend
+- Deploy backend separately as before
+
+## Open Questions
+- Should we add config validation UI on first startup?
+- Should backend port be auto-discovered if 8000 is in use?