fix(GRO-1171): restore UAT_PLAYBOOK and add coatType/petSizeCategory to buildPet

Address QA review findings on PR #12:
- Add coatType and petSizeCategory to buildPet defaults in packages/db/src/factories.ts
  to fix TypeScript typecheck failure
- Restore UAT_PLAYBOOK.md (was deleted during monorepo extraction) and add
  §4.15 Buffer Rules test cases

Co-Authored-By: Paperclip <noreply@paperclip.ing>

UAT_PLAYBOOK.md

@@ -183,6 +183,18 @@ GroomBook API is a Hono-based REST service (TypeScript/Node.js) powering the pet
 | TC-API-14.4 | Update group notes | PATCH /api/appointment-groups/{id} with notes | 200 OK, notes updated |
 | TC-API-14.5 | Cancel group | DELETE /api/appointment-groups/{id} | 200 OK, all appointments cancelled |
 
+### 4.15 Buffer Rules
+
+| # | Scenario | Steps | Expected |
+|---|----------|-------|----------|
+| TC-API-15.1 | List buffer rules | GET /api/admin/buffer-rules | 200 OK, list of active buffer rules returned |
+| TC-API-15.2 | Create buffer rule | POST /api/admin/buffer-rules with service, species, sizeCategory, bufferMinutes | 201 Created, buffer rule created |
+| TC-API-15.3 | Update buffer rule | PATCH /api/admin/buffer-rules/{id} with updated bufferMinutes | 200 OK, buffer rule updated |
+| TC-API-15.4 | Delete buffer rule | DELETE /api/admin/buffer-rules/{id} | 200 OK, buffer rule removed |
+| TC-API-15.5 | Reject invalid bufferMinutes | POST /api/admin/buffer-rules with bufferMinutes: -5 | 400 Bad Request, invalid bufferMinutes rejected |
+| TC-API-15.6 | Reject missing required fields | POST /api/admin/buffer-rules with service only | 400 Bad Request, species and sizeCategory required |
+| TC-API-15.7 | Booking uses buffer | Book appointment for pet with sizeCategory; verify duration reflects buffer | 201 Created, appointment duration includes buffer time |
+
 ## Pass/Fail Criteria
 
 **Pass:**

packages/db/src/factories.ts

@@ -105,6 +105,8 @@ export function buildPet(overrides: Partial<PetRow> & { clientId: string }): Pet
     photoKey: null,
     photoUploadedAt: null,
     image: null,
+    coatType: null,
+    petSizeCategory: null,
     createdAt: new Date("2025-01-01T00:00:00Z"),
     updatedAt: new Date("2025-01-01T00:00:00Z"),
   };