feat(GRO-1177): add GET /api/pets/:id/profile-summary endpoint

Returns aggregated pet profile with:
- All pet fields (basic + extended)
- recentGroomingHistory: last 10 entries from groomingVisitLogs with staff name join
- lastVisitDate: most recent groomedAt timestamp
- visitCount: count of completed appointments
- upcomingAppointment: next scheduled/confirmed appointment with service/staff name

Enforces same groomer RBAC as GET /:id. Returns 404 for non-existent pets.
Adds PetProfileSummary, GroomingHistoryEntry, and UpcomingAppointment types.
Adds unit tests covering: 404, 403, aggregated profile, empty history, no upcoming appt.
Updates UAT_PLAYBOOK.md §3 with TC-API-3.8 and TC-API-3.9.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

UAT_PLAYBOOK.md

@@ -57,6 +57,8 @@ GroomBook API is a Hono-based REST service (TypeScript/Node.js) powering the pet
 | TC-API-3.5 | Delete pet | DELETE /api/pets/{id} | 200 OK, pet deleted |
 | TC-API-3.6 | Upload pet photo | POST /api/pets/{id}/photo/upload-url, then confirm | 200 OK, photo uploaded and key stored |
 | TC-API-3.7 | View pet photo | GET /api/pets/{id}/photo | 200 OK, presigned URL returned |
+| TC-API-3.8 | Get pet profile summary | GET /api/pets/{id}/profile-summary | 200 OK, aggregated profile with grooming history, visit count, upcoming appointment |
+| TC-API-3.9 | Get pet profile summary — groomer restricted | GET /api/pets/{id}/profile-summary as groomer with no pet linkage | 403 Forbidden |
 
 ### 4.4 Appointment Scheduling