feat(02-01): add 8 Prisma models, 3 enums, Pet back-relations

- Append PostType, MilestoneType (16 values), ReportReason enums
- Add Post, PostImage, Milestone, Story, StoryView, Follow, Block, Report models
- Add Pet back-relations for all Phase 2 social graph relations
- Explicit named relations on all self-referential models (Follower/Followee, Blocker/Blocked, StoryViewer, Reporter)
- StoryView.storyId has NO onDelete cascade per D-08 (views survive story expiry)
- npx prisma validate + generate + db push all succeeded

prisma/schema.prisma

@@ -40,9 +40,149 @@ model Pet {
   name          String
   bio           String?
   adoptionStory String?
-  avatarKey     String? // R2 object key, NOT a full URL
+  avatarKey     String? // Supabase Storage object key, NOT a full URL
   createdAt     DateTime @default(now())
   updatedAt     DateTime @updatedAt
 
+  // Phase 2 back-relations
+  posts      Post[]
+  stories    Story[]
+  storyViews StoryView[] @relation("StoryViewer")
+  following  Follow[]    @relation("Follower")
+  followers  Follow[]    @relation("Followee")
+  blocking   Block[]     @relation("Blocker")
+  blockedBy  Block[]     @relation("Blocked")
+  reports    Report[]    @relation("Reporter")
+
   @@index([ownerId])
 }
+
+// ─── Phase 2 Enums ───────────────────────────────────────────────────────────
+
+enum PostType {
+  PHOTO
+  MILESTONE
+}
+
+enum MilestoneType {
+  BIRTHDAY
+  ADOPTION_DAY
+  FIRST_OUTING
+  VET_VISIT
+  LITTER
+  FOLLOWERS_500
+  FOLLOWERS_1K
+  FOLLOWERS_2_5K
+  FOLLOWERS_5K
+  FOLLOWERS_10K
+  FOLLOWERS_25K
+  FOLLOWERS_50K
+  FOLLOWERS_100K
+  FOLLOWERS_250K
+  FOLLOWERS_500K
+  FOLLOWERS_1M
+}
+
+enum ReportReason {
+  SPAM
+  HARASSMENT
+  INAPPROPRIATE
+  MISINFORMATION
+  OTHER
+}
+
+// ─── Phase 2 Models ──────────────────────────────────────────────────────────
+
+model Post {
+  id        String      @id @default(cuid())
+  pet       Pet         @relation(fields: [petId], references: [id], onDelete: Cascade)
+  petId     String
+  type      PostType    @default(PHOTO)
+  caption   String?     @db.VarChar(500)
+  images    PostImage[]
+  milestone Milestone?
+  createdAt DateTime    @default(now())
+  updatedAt DateTime    @updatedAt
+
+  @@index([petId, createdAt(sort: Desc)])
+}
+
+model PostImage {
+  id         String @id @default(cuid())
+  post       Post   @relation(fields: [postId], references: [id], onDelete: Cascade)
+  postId     String
+  storageKey String // Supabase Storage object key
+  position   Int // 0-based order in carousel
+  width      Int?
+  height     Int?
+
+  @@unique([postId, position])
+  @@index([postId])
+}
+
+model Milestone {
+  id            String        @id @default(cuid())
+  post          Post          @relation(fields: [postId], references: [id], onDelete: Cascade)
+  postId        String        @unique
+  milestoneType MilestoneType
+  notes         String?       @db.VarChar(500) // free text for 'litter' type (D-09)
+}
+
+model Story {
+  id         String      @id @default(cuid())
+  pet        Pet         @relation(fields: [petId], references: [id], onDelete: Cascade)
+  petId      String
+  storageKey String // Supabase Storage object key
+  expiresAt  DateTime // set to NOW() + 24 hours on create (D-07)
+  views      StoryView[]
+  createdAt  DateTime    @default(now())
+
+  @@index([petId, expiresAt]) // supports lazy-delete filter query
+}
+
+model StoryView {
+  story       Story    @relation(fields: [storyId], references: [id]) // NO onDelete:Cascade (D-08)
+  storyId     String
+  viewerPet   Pet      @relation("StoryViewer", fields: [viewerPetId], references: [id])
+  viewerPetId String
+  viewedAt    DateTime @default(now())
+
+  @@id([storyId, viewerPetId]) // deduplication: one view per viewer per story
+  @@index([viewedAt]) // supports 30-day cleanup job (D-08)
+}
+
+model Follow {
+  follower      Pet      @relation("Follower", fields: [followerPetId], references: [id], onDelete: Cascade)
+  followerPetId String
+  followee      Pet      @relation("Followee", fields: [followeePetId], references: [id], onDelete: Cascade)
+  followeePetId String
+  createdAt     DateTime @default(now())
+
+  @@id([followerPetId, followeePetId])
+  @@index([followerPetId])
+  @@index([followeePetId])
+}
+
+model Block {
+  blocker      Pet      @relation("Blocker", fields: [blockerPetId], references: [id], onDelete: Cascade)
+  blockerPetId String
+  blocked      Pet      @relation("Blocked", fields: [blockedPetId], references: [id], onDelete: Cascade)
+  blockedPetId String
+  createdAt    DateTime @default(now())
+
+  @@id([blockerPetId, blockedPetId])
+  @@index([blockerPetId])
+}
+
+model Report {
+  id            String       @id @default(cuid())
+  reporter      Pet          @relation("Reporter", fields: [reporterPetId], references: [id])
+  reporterPetId String
+  targetPostId  String? // null if reporting a profile
+  targetPetId   String? // null if reporting a post
+  reason        ReportReason
+  notes         String?      @db.VarChar(500)
+  createdAt     DateTime     @default(now())
+
+  @@index([reporterPetId])
+}