feat: config files, settings screen, hardware check

- Add config.py with multi-source config (YAML, .env, env vars)
- Add .env.example and config.yaml.example
- Add settings API endpoints (GET/POST /api/v1/settings)
- Add status endpoint (GET /api/v1/status) with hardware subsystem check
- Add settings screen to web client (protected by API token)
- Add localization strings for settings UI
- Add tests for config module and new endpoints
- Update README with config documentation

server/requirements.txt

@@ -2,6 +2,7 @@
 fastapi>=0.100.0
 uvicorn[standard]>=0.23.0
 pydantic>=2.0.0
+pyyaml>=6.0
 
 # Windows APIs
 winsdk>=1.0.0