fix(security): enforce ownership on 4 IDOR read/bind endpoints (M2-M5)

- M2 GET /insurance/{id}: was unguarded; now owner-or-admin (403 otherwise) —
  stops reading another doctor's negotiated price by id enumeration.
- M3 GET /clinic-pro/doctor-address/{id}: add the same owner/admin check the
  sibling PATCH/DELETE already had.
- M4 POST/PATCH /service-item: staff_uuid must belong to the caller's tenant
  (entity_type/entity_id) → 422; stops binding another tenant's staff.
- M5 appointment-settings list endpoints (date-override/holidays/
  available-locations): add the per-doctor ownership check the sibling
  single-record endpoints already enforce.

Regressions (6 negative cases fail without the fixes):
DoctorInsuranceOwnershipTest, DoctorAddressOwnershipTest,
ServiceItemStaffOwnershipTest, AppointmentSettingsListOwnershipTest.

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

docs/api/appointment-settings.md

@@ -248,7 +248,7 @@ Override a specific date — mark it inactive (day off) or give it custom sessio
 
 Get all date overrides for a doctor.
 
-**Permission:** `AUTH` (class-level)
+**Permission:** `AUTH` — must be the owning doctor or `ROLE_ADMIN` (`403 ERR_AUTH_006` otherwise).
 
 ### Response `200`
 ```json
@@ -425,7 +425,7 @@ Mark a date range as holiday — all slots blocked, no overrides apply.
 
 Get all holidays for a doctor.
 
-**Permission:** `AUTH` (class-level)
+**Permission:** `AUTH` — must be the owning doctor or `ROLE_ADMIN` (`403 ERR_AUTH_006` otherwise).
 
 ### Response `200`
 ```json
@@ -573,7 +573,7 @@ The `SlotCalculatorService` calculates available slots in this priority order:
 
 ### `GET /api/v1/appointment-settings/available-locations/{doctorUuid}`
 
-**Permission:** Public
+**Permission:** `AUTH` — must be the owning doctor or `ROLE_ADMIN` (`403 ERR_AUTH_006` otherwise).
 
 Returns all locations a doctor can assign as `location_id` in their schedule sessions. Includes both the doctor's personal addresses and the addresses of all clinics they belong to.