- Add _settings_schema to all 9 sensor classes (bme280, ens210, ina219, shtc3,
lafvin_ups_3s, waveshare_ups_d, waveshare_ups_e, hardware_stats, openhop_modem)
- Implement GET /sensors/types, GET /sensors/config, POST /sensors/config,
POST /sensors/read endpoints in api_endpoints.py
- Update openapi.yaml with Sensors tag and endpoint schemas
- Add underscore-to-slash path mapping in contract checker
- Add sensors to contract allowlist