feat: member portal Sprint 11 — Memories / Gallery

- GalleryAlbum + GalleryItem models + migration (publish gate, cover image, ordered items)
- GalleryModule: admin CRUD for albums + items
- Member endpoints: GET /my/memories (published albums w/ cover + count), GET /my/memories/:id (album + photos)
- /my/memories page: album grid with cover thumbnails
- /my/memories/[id] page: photo grid with captions
- Memories nav item; register GalleryModule

Completes Phase 2 (Intelligence) of the member portal — Sprints 9-11.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/api/prisma/schema.prisma

@@ -98,6 +98,8 @@ model Tenant {
   askAIQueries       AskAIQuery[]
   knowledgeBoards    KnowledgeBoard[]
   knowledgeItems     KnowledgeItem[]
+  galleryAlbums      GalleryAlbum[]
+  galleryItems       GalleryItem[]
 }
 
 enum AdminRole {
@@ -799,3 +801,39 @@ model KnowledgeItem {
   @@index([tenantId, status])
   @@index([boardId, status])
 }
+
+// ============================================================================
+// Memories / Gallery
+// ============================================================================
+
+model GalleryAlbum {
+  id          String   @id @default(cuid())
+  tenantId    String
+  tenant      Tenant   @relation(fields: [tenantId], references: [id])
+  title       String
+  description String?
+  coverUrl    String?
+  isPublished Boolean  @default(false)
+  createdBy   String
+  createdAt   DateTime @default(now())
+  updatedAt   DateTime @updatedAt
+
+  items GalleryItem[]
+
+  @@index([tenantId, isPublished])
+}
+
+model GalleryItem {
+  id        String       @id @default(cuid())
+  albumId   String
+  album     GalleryAlbum @relation(fields: [albumId], references: [id], onDelete: Cascade)
+  tenantId  String
+  tenant    Tenant       @relation(fields: [tenantId], references: [id])
+  mediaUrl  String
+  caption   String?
+  sortOrder Int          @default(0)
+  createdAt DateTime     @default(now())
+
+  @@index([albumId])
+  @@index([tenantId])
+}