diff --git a/packages/db-cn/prisma/schema.prisma b/packages/db-cn/prisma/schema.prisma
index a7865b9..35fe22b 100644
--- a/packages/db-cn/prisma/schema.prisma
+++ b/packages/db-cn/prisma/schema.prisma
@@ -174,6 +174,10 @@ model photos {
   entityVersion   Int       @default(1)
   @@index([albumId, visibility, publishedAt, id])
   @@index([albumId, uploaderId, uploadedAt])
+  // 查重索引声明回填（P0-1 层 2）：索引由迁移 20260928120000 手写 SQL 创建
+  // （同相册+上传者+字节数匹配，命中即 409 PHOTO_DUPLICATE）；此处补声明使
+  // schema ↔ 迁移历史一致，消除 migrate dev 误提议 DROP 的漂移（2026-09-28）。
+  @@index([albumId, uploaderId, bytes], map: "idx_photos_dedup")
 }
 model photo_variants {
   photoId  String  @db.VarChar(64)