Add locationtypes + location tree (ADR-001)

- New locationtypes lookup (LocationType model) seeded with section, cell,
  subcell, operation, meetingroom, lab, office, storage, hallway,
  networkcloset, building.
- locations gains locationtypeid + parentlocationid (self-FK) for the site
  location tree. Migration 7c03; cli reference-data seeds the types.
- GET /api/locations/types; locations CRUD accepts type + parent; list/detail
  return locationtypename + parentlocationname.
- Locations settings page: Type column + Type/Parent selectors in the modal.

Realizes the operation-as-Location model (operations are locations with
locationtypeid='operation').

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/api/index.js

@@ -202,6 +202,11 @@ export const locationsApi = {
   },
   delete(id) {
     return api.delete(`/locations/${id}`)
+  },
+  types: {
+    list() {
+      return api.get('/locations/types')
+    }
   }
 }