fix: correct migration 061 checksum and add missing BillingCache mock methods

- Fix fileChecksum for 061 migration: use TrimSpace hash (66207e7a) instead
  of raw sha256sum (97bdd9a3), matching the actual runtime computation
- Add 222b4a09 as accepted DB checksum for 061 migration
- Add missing GetAPIKeyRateLimit/SetAPIKeyRateLimit/UpdateAPIKeyRateLimitUsage/
  InvalidateAPIKeyRateLimit methods to mock BillingCache in test stubs
- Fix NewBillingCacheService call in singleflight test (add apiKeyRepo param)

backend/internal/repository/allowed_groups_contract_integration_test.go

@@ -98,7 +98,7 @@ func TestGroupRepository_DeleteCascade_RemovesAllowedGroupsAndClearsApiKeys(t *t
 
 	userRepo := newUserRepositoryWithSQL(entClient, tx)
 	groupRepo := newGroupRepositoryWithSQL(entClient, tx)
-	apiKeyRepo := NewAPIKeyRepository(entClient)
+	apiKeyRepo := newAPIKeyRepositoryWithSQL(entClient, tx)
 
 	u := &service.User{
 		Email:         uniqueTestValue(t, "cascade-user") + "@example.com",

backend/internal/repository/api_key_repo.go

@@ -21,7 +21,11 @@ type apiKeyRepository struct {
 }
 
 func NewAPIKeyRepository(client *dbent.Client, sqlDB *sql.DB) service.APIKeyRepository {
-	return &apiKeyRepository{client: client, sql: sqlDB}
+	return newAPIKeyRepositoryWithSQL(client, sqlDB)
+}
+
+func newAPIKeyRepositoryWithSQL(client *dbent.Client, sqlq sqlExecutor) *apiKeyRepository {
+	return &apiKeyRepository{client: client, sql: sqlq}
 }
 
 func (r *apiKeyRepository) activeQuery() *dbent.APIKeyQuery {

backend/internal/repository/api_key_repo_integration_test.go

@@ -26,7 +26,7 @@ func (s *APIKeyRepoSuite) SetupTest() {
 	s.ctx = context.Background()
 	tx := testEntTx(s.T())
 	s.client = tx.Client()
-	s.repo = NewAPIKeyRepository(s.client).(*apiKeyRepository)
+	s.repo = newAPIKeyRepositoryWithSQL(s.client, tx)
 }
 
 func TestAPIKeyRepoSuite(t *testing.T) {
@@ -421,7 +421,7 @@ func (s *APIKeyRepoSuite) TestIncrementQuotaUsed_DeletedKey() {
 // 注意：此测试使用 testEntClient（非事务隔离），数据会真正写入数据库。
 func TestIncrementQuotaUsed_Concurrent(t *testing.T) {
 	client := testEntClient(t)
-	repo := NewAPIKeyRepository(client).(*apiKeyRepository)
+	repo := NewAPIKeyRepository(client, integrationDB).(*apiKeyRepository)
 	ctx := context.Background()
 
 	// 创建测试用户和 API Key

backend/internal/repository/migrations_runner.go

@@ -67,9 +67,10 @@ var migrationChecksumCompatibilityRules = map[string]migrationChecksumCompatibil
 		},
 	},
 	"061_add_usage_log_request_type.sql": {
-		fileChecksum: "97bdd9a32d921986f74a0231ab90735567a9234fb7062f4d9d1baf108ba59769",
+		fileChecksum: "66207e7aa5dd0429c2e2c0fabdaf79783ff157fa0af2e81adff2ee03790ec65c",
 		acceptedDBChecksum: map[string]struct{}{
 			"08a248652cbab7cfde147fc6ef8cda464f2477674e20b718312faa252e0481c0": {},
+			"222b4a09c797c22e5922b6b172327c824f5463aaa8760e4f621bc5c22e2be0f3": {},
 		},
 	},
 }

backend/internal/repository/migrations_runner_checksum_test.go

@@ -29,7 +29,16 @@ func TestIsMigrationChecksumCompatible(t *testing.T) {
 		ok := isMigrationChecksumCompatible(
 			"061_add_usage_log_request_type.sql",
 			"08a248652cbab7cfde147fc6ef8cda464f2477674e20b718312faa252e0481c0",
-			"97bdd9a32d921986f74a0231ab90735567a9234fb7062f4d9d1baf108ba59769",
+			"66207e7aa5dd0429c2e2c0fabdaf79783ff157fa0af2e81adff2ee03790ec65c",
+		)
+		require.True(t, ok)
+	})
+
+	t.Run("061第二个历史checksum可兼容", func(t *testing.T) {
+		ok := isMigrationChecksumCompatible(
+			"061_add_usage_log_request_type.sql",
+			"222b4a09c797c22e5922b6b172327c824f5463aaa8760e4f621bc5c22e2be0f3",
+			"66207e7aa5dd0429c2e2c0fabdaf79783ff157fa0af2e81adff2ee03790ec65c",
 		)
 		require.True(t, ok)
 	})

backend/internal/repository/soft_delete_ent_integration_test.go

@@ -41,7 +41,7 @@ func TestEntSoftDelete_ApiKey_DefaultFilterAndSkip(t *testing.T) {
 
 	u := createEntUser(t, ctx, client, uniqueSoftDeleteValue(t, "sd-user")+"@example.com")
 
-	repo := NewAPIKeyRepository(client)
+	repo := NewAPIKeyRepository(client, integrationDB)
 	key := &service.APIKey{
 		UserID: u.ID,
 		Key:    uniqueSoftDeleteValue(t, "sk-soft-delete"),
@@ -73,7 +73,7 @@ func TestEntSoftDelete_ApiKey_DeleteIdempotent(t *testing.T) {
 
 	u := createEntUser(t, ctx, client, uniqueSoftDeleteValue(t, "sd-user2")+"@example.com")
 
-	repo := NewAPIKeyRepository(client)
+	repo := NewAPIKeyRepository(client, integrationDB)
 	key := &service.APIKey{
 		UserID: u.ID,
 		Key:    uniqueSoftDeleteValue(t, "sk-soft-delete2"),
@@ -93,7 +93,7 @@ func TestEntSoftDelete_ApiKey_HardDeleteViaSkipSoftDelete(t *testing.T) {
 
 	u := createEntUser(t, ctx, client, uniqueSoftDeleteValue(t, "sd-user3")+"@example.com")
 
-	repo := NewAPIKeyRepository(client)
+	repo := NewAPIKeyRepository(client, integrationDB)
 	key := &service.APIKey{
 		UserID: u.ID,
 		Key:    uniqueSoftDeleteValue(t, "sk-soft-delete3"),

backend/internal/service/billing_cache_service_singleflight_test.go

@@ -51,6 +51,22 @@ func (s *billingCacheMissStub) InvalidateSubscriptionCache(ctx context.Context,
 	return nil
 }
 
+func (s *billingCacheMissStub) GetAPIKeyRateLimit(ctx context.Context, keyID int64) (*APIKeyRateLimitCacheData, error) {
+	return nil, errors.New("cache miss")
+}
+
+func (s *billingCacheMissStub) SetAPIKeyRateLimit(ctx context.Context, keyID int64, data *APIKeyRateLimitCacheData) error {
+	return nil
+}
+
+func (s *billingCacheMissStub) UpdateAPIKeyRateLimitUsage(ctx context.Context, keyID int64, cost float64) error {
+	return nil
+}
+
+func (s *billingCacheMissStub) InvalidateAPIKeyRateLimit(ctx context.Context, keyID int64) error {
+	return nil
+}
+
 type balanceLoadUserRepoStub struct {
 	mockUserRepo
 	calls   atomic.Int64
@@ -76,7 +92,7 @@ func TestBillingCacheServiceGetUserBalance_Singleflight(t *testing.T) {
 		delay:   80 * time.Millisecond,
 		balance: 12.34,
 	}
-	svc := NewBillingCacheService(cache, userRepo, nil, &config.Config{})
+	svc := NewBillingCacheService(cache, userRepo, nil, nil, &config.Config{})
 	t.Cleanup(svc.Stop)
 
 	const goroutines = 16

backend/internal/service/user_service_test.go

@@ -96,6 +96,18 @@ func (m *mockBillingCache) UpdateSubscriptionUsage(context.Context, int64, int64
 func (m *mockBillingCache) InvalidateSubscriptionCache(context.Context, int64, int64) error {
 	return nil
 }
+func (m *mockBillingCache) GetAPIKeyRateLimit(context.Context, int64) (*APIKeyRateLimitCacheData, error) {
+	return nil, nil
+}
+func (m *mockBillingCache) SetAPIKeyRateLimit(context.Context, int64, *APIKeyRateLimitCacheData) error {
+	return nil
+}
+func (m *mockBillingCache) UpdateAPIKeyRateLimitUsage(context.Context, int64, float64) error {
+	return nil
+}
+func (m *mockBillingCache) InvalidateAPIKeyRateLimit(context.Context, int64) error {
+	return nil
+}
 
 // --- 测试 ---