feat: pet photo upload via presigned S3 URLs (GH #93, GRO-123)

- DB migration 0012: add photo_key and photo_uploaded_at columns to pets table
- S3 client utility (apps/api/src/lib/s3.ts): presigned PUT/GET, delete via Rook-Ceph RGW
- API photo routes on petsRouter:
  - POST /:petId/photo/upload-url — returns presigned PUT URL + object key
  - POST /:petId/photo/confirm    — records key in DB after successful upload
  - DELETE /:petId/photo          — deletes from storage and clears DB
  - GET /:petId/photo             — returns presigned GET URL
- RBAC: all staff roles (manager, receptionist, groomer) may upload/delete photos;
  restructured index.ts guards so groomer-accessible photo paths don't overlap
  with the manager/receptionist-only general pets write guard
- Frontend PetPhotoDisplay: responsive image with shimmer skeleton and paw placeholder
- Frontend PetPhotoUpload: client-side resize to max 1200px, XHR with progress,
  presigned PUT flow — binary data never passes through the API server
- Wired both components into Clients.tsx staff portal pet cards
- Unit tests: 14 test cases covering all four routes (happy path + error cases)

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

packages/db/src/schema.ts

@@ -81,6 +81,8 @@ export const pets = pgTable("pets", {
   shampooPreference: text("shampoo_preference"),
   specialCareNotes: text("special_care_notes"),
   customFields: jsonb("custom_fields").$type<Record<string, string>>().notNull().default({}),
+  photoKey: text("photo_key"),
+  photoUploadedAt: timestamp("photo_uploaded_at"),
   createdAt: timestamp("created_at").notNull().defaultNow(),
   updatedAt: timestamp("updated_at").notNull().defaultNow(),
 });