fix: 修复 fileid索引

prisma/migrations/20260517000000_add_screenshot_file_id_index/migration.sql

@@ -0,0 +1,2 @@
+-- CreateIndex
+CREATE INDEX "screenshots_fileId_idx" ON "screenshots"("fileId");

prisma/schema.prisma

@@ -75,6 +75,7 @@ model Screenshot {
   record Record @relation(fields: [recordId], references: [id], onDelete: Cascade)
 
   @@index([recordId])
+  @@index([fileId])
   @@index([objectName])
   @@map("screenshots")
 }