Ruff auto-fix: unused Optional imports in sectors router and link
schemas, unused Site import in device service, unused datetime
imports in trend detector, unused text import in site service,
and f-string without placeholders in signal history service.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- Create sectors table migration (034) with RLS and devices.sector_id FK
- Add Sector ORM model with site_id and tenant_id foreign keys
- Add SectorCreate/Update/Response/ListResponse Pydantic schemas
- Implement sector_service with CRUD and device assignment functions
- Add sectors router with GET/POST/PUT/DELETE and device sector assignment
- Register sectors router in main.py
- Add sector_id and sector_name to Device model and DeviceResponse
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
