- Reject duplicate site codes per client (case-insensitive); site code is immutable once set
- Delete tombstones the site and requires the DeleteSites permission (Admin, Scheduler)
- GET /api/locations/{id}/open-work-orders returns the open count and ids
- PATCH /api/locations/{id}/contact-info saves contacts and notes from the work-order Site dialog
- Add nullable Locations.Notes, used as the site-level POC notes fallback
