feat: Extract hardcoded configs to environment variables

- Add environment variable configuration for backend and frontend
- Backend: DB_POOL_SIZE, JWT_EXPIRE_HOURS, timeout configs, directory paths
- Frontend: VITE_API_BASE_URL, VITE_UPLOAD_TIMEOUT, Whisper configs
- Create deployment script (scripts/deploy-backend.sh)
- Create 1Panel deployment guide (docs/1panel-deployment.md)
- Update DEPLOYMENT.md with env var documentation
- Create README.md with project overview
- Remove obsolete PRD.md, SDD.md, TDD.md (replaced by OpenSpec)
- Keep CORS allow_origins=["*"] for Electron EXE distribution

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

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

client/.env.example

@@ -0,0 +1,39 @@
+# =============================================================================
+# Meeting Assistant Frontend Configuration
+# Copy this file to .env and fill in your values
+# =============================================================================
+
+# -----------------------------------------------------------------------------
+# API Configuration (Vite build-time variables)
+# -----------------------------------------------------------------------------
+# Backend API base URL
+# For development: http://localhost:8000/api
+# For production: http://<server-ip>:<port>/api or https://api.example.com/api
+VITE_API_BASE_URL=http://localhost:8000/api
+
+# Upload timeout in milliseconds (default: 600000 = 10 minutes)
+VITE_UPLOAD_TIMEOUT=600000
+
+# Application title (shown in window title)
+VITE_APP_TITLE=Meeting Assistant
+
+# -----------------------------------------------------------------------------
+# Sidecar/Whisper Configuration (Electron runtime variables)
+# -----------------------------------------------------------------------------
+# These environment variables are read by Electron main process at runtime
+# and passed to the Sidecar (Whisper transcription service)
+
+# Whisper model size
+# Options: tiny, base, small, medium, large
+# Larger models are more accurate but require more memory and are slower
+WHISPER_MODEL=medium
+
+# Execution device
+# Options: cpu, cuda
+# Use "cuda" if you have an NVIDIA GPU with CUDA support
+WHISPER_DEVICE=cpu
+
+# Compute precision
+# Options: int8, float16, float32
+# int8 is fastest but less accurate, float32 is most accurate but slowest
+WHISPER_COMPUTE=int8