feat(api): add product_families schema and migration

apps/api/prisma/schema.prisma

@@ -30,9 +30,15 @@ model OriginGood {
   goodPrice     Decimal? @map("good_price") @db.Decimal(12, 2)
   delisted      Boolean  @default(false)
   source        OriginGoodSource @default(SDS)
+  familyId       BigInt?  @map("family_id")
+  skuCode        String?  @map("sku_code")
+  logisticsLabel String?  @map("logistics_label")
+  craftLabel     String?  @map("craft_label")
+  warehouseLabel String?  @map("warehouse_label")
   createdAt     DateTime @default(now()) @map("created_at") @db.Timestamptz(6)
   updatedAt     DateTime @default(now()) @updatedAt @map("updated_at") @db.Timestamptz(6)
 
+  family    ProductFamily?  @relation(fields: [familyId], references: [id], onDelete: SetNull, onUpdate: NoAction)
   goods    Good[]
   detail   OriginGoodDetail?
   variants OriginGoodVariant[]
@@ -40,6 +46,10 @@ model OriginGood {
 
   @@index([sdsCategoryId])
   @@index([source])
+  @@index([familyId])
+  @@index([skuCode])
+  @@index([logisticsLabel])
+  @@index([craftLabel])
   @@map("origin_goods")
 }
 
@@ -118,6 +128,7 @@ model Country {
 
   goods     Good[]
   positions Position[]
+  families  ProductFamily[]
 
   @@map("countries")
 }
@@ -136,6 +147,7 @@ model Category {
   children  Category[] @relation("CategoryToCategory")
   goods     Good[]
   positions Position[]
+  families  ProductFamily[]
 
   @@index([parentCategoryId])
   @@map("categories")
@@ -258,6 +270,56 @@ model GoodOriginGood {
   @@map("good_origin_goods")
 }
 
+// ---------- Product Families (SPU layer over origin goods) ----------
+// 设计文档：docs/superpowers/specs/2026-08-28-product-family-merge-design.md
+// primaryOriginGoodId 刻意不建 FK：避免与 origin_goods 相互依赖，主链接被同步删除时由服务层清理。
+model ProductFamily {
+  id                  BigInt   @id @default(autoincrement()) @map("family_id")
+  familyCode          String?  @unique @map("family_code")
+  familyName          String   @map("family_name")
+  familyImage         String?  @map("family_image")
+  countryId           BigInt?  @map("country_id")
+  categoryId          BigInt?  @map("category_id")
+  primaryOriginGoodId BigInt?  @map("primary_origin_good_id")
+  detail              Json?
+  sizeChart           Json?    @map("size_chart")
+  packageSpecs        Json?    @map("package_specs")
+  priceMatrix         Json?    @map("price_matrix")
+  autoManaged         Boolean  @default(true) @map("auto_managed")
+  stale               Boolean  @default(false)
+  createdAt           DateTime @default(now()) @map("created_at") @db.Timestamptz(6)
+  updatedAt           DateTime @updatedAt @map("updated_at") @db.Timestamptz(6)
+
+  originGoods    OriginGood[]
+  priceOverrides FamilyPriceOverride[]
+  country        Country?  @relation(fields: [countryId], references: [id], onDelete: SetNull, onUpdate: NoAction)
+  category       Category? @relation(fields: [categoryId], references: [id], onDelete: SetNull, onUpdate: NoAction)
+
+  @@index([countryId])
+  @@index([categoryId])
+  @@map("product_families")
+}
+
+// ---------- Family Price Overrides (manual per-cell price) ----------
+// 独立于推导矩阵：重算只重建推导部分，本表永不被动覆盖。
+model FamilyPriceOverride {
+  id        BigInt   @id @default(autoincrement()) @map("family_price_override_id")
+  familyId  BigInt   @map("family_id")
+  sizeId    String   @map("size_id")
+  colorId   String   @map("color_id")
+  craft     String
+  logistics String
+  price     Decimal  @db.Decimal(12, 2)
+  note      String?
+  createdAt DateTime @default(now()) @map("created_at") @db.Timestamptz(6)
+  updatedAt DateTime @updatedAt @map("updated_at") @db.Timestamptz(6)
+
+  family ProductFamily @relation(fields: [familyId], references: [id], onDelete: Cascade, onUpdate: NoAction)
+
+  @@unique([familyId, sizeId, colorId, craft, logistics])
+  @@map("family_price_overrides")
+}
+
 // ---------- Users (admin authentication) ----------
 enum Role {
   ADMIN