fix(database): 资源上传幂等 - 补齐生产库 upload_key 迁移

backend/internal/database/migrations.go

@@ -10,11 +10,12 @@ import (
 	"gorm.io/gorm"
 )
 
-const CurrentSchemaVersion int64 = 3
+const CurrentSchemaVersion int64 = 4
 
 const baselineSchemaChecksum = "sha256:open-ai-canvas-schema-v1-20260830"
 const schemaMigrationAppliedAtIndexChecksum = "sha256:schema-migrations-applied-at-index-v2-20260830"
 const assetTaxonomyCandidateIdentityChecksum = "sha256:asset-taxonomy-candidate-identity-v3-20260831-r1"
+const resourceUploadKeyChecksum = "sha256:resource-upload-key-v4-20260901"
 
 const postgresSchemaMigrationLockID int64 = 73123910420260830
 
@@ -44,6 +45,7 @@ var schemaMigrations = []migration{
 	{version: 1, name: "baseline_gorm_schema", checksum: baselineSchemaChecksum, apply: migrateSchemaV1},
 	{version: 2, name: "schema_migrations_applied_at_index", checksum: schemaMigrationAppliedAtIndexChecksum, apply: migrateSchemaV2},
 	{version: 3, name: "asset_taxonomy_candidate_identity", checksum: assetTaxonomyCandidateIdentityChecksum, apply: migrateSchemaV3},
+	{version: 4, name: "resource_upload_key", checksum: resourceUploadKeyChecksum, apply: migrateSchemaV4},
 }
 
 func migrateSchemaV2(tx *gorm.DB) error {
@@ -89,6 +91,21 @@ func migrateSchemaV3(tx *gorm.DB) error {
 	return tx.Exec("CREATE UNIQUE INDEX IF NOT EXISTS idx_project_asset_candidates_pending_identity ON project_asset_candidates(project_id, category, name_key) WHERE status = 'pending_confirmation' AND name_key <> ''").Error
 }
 
+func migrateSchemaV4(tx *gorm.DB) error {
+	if !tx.Migrator().HasTable(&model.Resource{}) {
+		return fmt.Errorf("资源表不存在")
+	}
+	if !tx.Migrator().HasColumn(&model.Resource{}, "upload_key") {
+		if err := tx.Migrator().AddColumn(&model.Resource{}, "UploadKey"); err != nil {
+			return fmt.Errorf("增加资源上传幂等列：%w", err)
+		}
+	}
+	if err := tx.Exec("CREATE UNIQUE INDEX IF NOT EXISTS idx_resources_user_upload_key ON resources (user_id, upload_key)").Error; err != nil {
+		return fmt.Errorf("创建资源上传幂等索引：%w", err)
+	}
+	return nil
+}
+
 func MigrateSchema(db *gorm.DB) error {
 	return db.Transaction(func(tx *gorm.DB) error {
 		if tx.Dialector.Name() == "postgres" {

backend/internal/database/migrations_test.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"strings"
 	"testing"
+	"time"
 
 	"infinite-canvas/backend/internal/model"
 
@@ -88,6 +89,50 @@ func TestMigrateSchemaV3NormalizesLegacyAccessoryCategory(t *testing.T) {
 	}
 }
 
+func TestMigrateSchemaV4AddsResourceUploadKeyToExistingSchema(t *testing.T) {
+	db, err := Open(Config{Driver: "sqlite", DSN: "file:migration-resource-upload-key?mode=memory&cache=shared"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := db.Exec(`CREATE TABLE resources (id TEXT PRIMARY KEY, user_id TEXT NOT NULL)`).Error; err != nil {
+		t.Fatal(err)
+	}
+	if err := db.AutoMigrate(&schemaMigration{}); err != nil {
+		t.Fatal(err)
+	}
+	for _, item := range schemaMigrations[:3] {
+		if err := db.Create(&schemaMigration{Version: item.version, Name: item.name, Checksum: item.checksum, AppliedAt: time.Now().UTC()}).Error; err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	if err := MigrateSchema(db); err != nil {
+		t.Fatalf("migrate existing schema: %v", err)
+	}
+	if !db.Migrator().HasColumn(&model.Resource{}, "upload_key") {
+		t.Fatal("resource upload_key column was not added")
+	}
+	if !db.Migrator().HasIndex(&model.Resource{}, "idx_resources_user_upload_key") {
+		t.Fatal("resource upload key index was not added")
+	}
+	var status SchemaStatus
+	status, err = ReadSchemaStatus(db)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !status.Ready || status.Current != 4 {
+		t.Fatalf("unexpected schema status: %#v", status)
+	}
+
+	firstKey := "same-upload"
+	if err := db.Exec(`INSERT INTO resources (id, user_id, upload_key) VALUES (?, ?, ?)`, "resource-1", "user-1", firstKey).Error; err != nil {
+		t.Fatal(err)
+	}
+	if err := db.Exec(`INSERT INTO resources (id, user_id, upload_key) VALUES (?, ?, ?)`, "resource-2", "user-1", firstKey).Error; err == nil {
+		t.Fatal("duplicate resource upload key should be rejected")
+	}
+}
+
 func TestMigrateSchemaRollsBackFailedMigration(t *testing.T) {
 	db, err := Open(Config{Driver: "sqlite", DSN: "file:migration-rollback?mode=memory&cache=shared"})
 	if err != nil {