fix(billing): 修复 OpenAI fast 档位计费并补齐展示

- 打通 service_tier 在 OpenAI HTTP、WS、passthrough 与 usage 记录中的传递
- 修正 priority/flex 计费逻辑，并将 fast 归一化为 priority
- 在用户端和管理端补齐服务档位与计费明细展示
- 补齐前后端测试，并修复 WS 限流信号重复持久化导致的全量回归失败

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/internal/repository/usage_log_repo.go

@@ -22,7 +22,7 @@ import (
 	"github.com/lib/pq"
 )
 
-const usageLogSelectColumns = "id, user_id, api_key_id, account_id, request_id, model, group_id, subscription_id, input_tokens, output_tokens, cache_creation_tokens, cache_read_tokens, cache_creation_5m_tokens, cache_creation_1h_tokens, input_cost, output_cost, cache_creation_cost, cache_read_cost, total_cost, actual_cost, rate_multiplier, account_rate_multiplier, billing_type, request_type, stream, openai_ws_mode, duration_ms, first_token_ms, user_agent, ip_address, image_count, image_size, media_type, reasoning_effort, cache_ttl_overridden, created_at"
+const usageLogSelectColumns = "id, user_id, api_key_id, account_id, request_id, model, group_id, subscription_id, input_tokens, output_tokens, cache_creation_tokens, cache_read_tokens, cache_creation_5m_tokens, cache_creation_1h_tokens, input_cost, output_cost, cache_creation_cost, cache_read_cost, total_cost, actual_cost, rate_multiplier, account_rate_multiplier, billing_type, request_type, stream, openai_ws_mode, duration_ms, first_token_ms, user_agent, ip_address, image_count, image_size, media_type, service_tier, reasoning_effort, cache_ttl_overridden, created_at"
 
 // dateFormatWhitelist 将 granularity 参数映射为 PostgreSQL TO_CHAR 格式字符串，防止外部输入直接拼入 SQL
 var dateFormatWhitelist = map[string]string{
@@ -135,6 +135,7 @@ func (r *usageLogRepository) Create(ctx context.Context, log *service.UsageLog)
 			image_count,
 			image_size,
 			media_type,
+			service_tier,
 			reasoning_effort,
 			cache_ttl_overridden,
 			created_at
@@ -144,7 +145,7 @@ func (r *usageLogRepository) Create(ctx context.Context, log *service.UsageLog)
 			$8, $9, $10, $11,
 			$12, $13,
 			$14, $15, $16, $17, $18, $19,
-			$20, $21, $22, $23, $24, $25, $26, $27, $28, $29, $30, $31, $32, $33, $34, $35
+			$20, $21, $22, $23, $24, $25, $26, $27, $28, $29, $30, $31, $32, $33, $34, $35, $36
 		)
 		ON CONFLICT (request_id, api_key_id) DO NOTHING
 		RETURNING id, created_at
@@ -158,6 +159,7 @@ func (r *usageLogRepository) Create(ctx context.Context, log *service.UsageLog)
 	ipAddress := nullString(log.IPAddress)
 	imageSize := nullString(log.ImageSize)
 	mediaType := nullString(log.MediaType)
+	serviceTier := nullString(log.ServiceTier)
 	reasoningEffort := nullString(log.ReasoningEffort)
 
 	var requestIDArg any
@@ -198,6 +200,7 @@ func (r *usageLogRepository) Create(ctx context.Context, log *service.UsageLog)
 		log.ImageCount,
 		imageSize,
 		mediaType,
+		serviceTier,
 		reasoningEffort,
 		log.CacheTTLOverridden,
 		createdAt,
@@ -2505,6 +2508,7 @@ func scanUsageLog(scanner interface{ Scan(...any) error }) (*service.UsageLog, e
 		imageCount            int
 		imageSize             sql.NullString
 		mediaType             sql.NullString
+		serviceTier           sql.NullString
 		reasoningEffort       sql.NullString
 		cacheTTLOverridden    bool
 		createdAt             time.Time
@@ -2544,6 +2548,7 @@ func scanUsageLog(scanner interface{ Scan(...any) error }) (*service.UsageLog, e
 		&imageCount,
 		&imageSize,
 		&mediaType,
+		&serviceTier,
 		&reasoningEffort,
 		&cacheTTLOverridden,
 		&createdAt,
@@ -2614,6 +2619,9 @@ func scanUsageLog(scanner interface{ Scan(...any) error }) (*service.UsageLog, e
 	if mediaType.Valid {
 		log.MediaType = &mediaType.String
 	}
+	if serviceTier.Valid {
+		log.ServiceTier = &serviceTier.String
+	}
 	if reasoningEffort.Valid {
 		log.ReasoningEffort = &reasoningEffort.String
 	}

backend/internal/repository/usage_log_repo_request_type_test.go

@@ -71,6 +71,7 @@ func TestUsageLogRepositoryCreateSyncRequestTypeAndLegacyFields(t *testing.T) {
 			log.ImageCount,
 			sqlmock.AnyArg(), // image_size
 			sqlmock.AnyArg(), // media_type
+			sqlmock.AnyArg(), // service_tier
 			sqlmock.AnyArg(), // reasoning_effort
 			log.CacheTTLOverridden,
 			createdAt,
@@ -81,12 +82,76 @@ func TestUsageLogRepositoryCreateSyncRequestTypeAndLegacyFields(t *testing.T) {
 	require.NoError(t, err)
 	require.True(t, inserted)
 	require.Equal(t, int64(99), log.ID)
+	require.Nil(t, log.ServiceTier)
 	require.Equal(t, service.RequestTypeWSV2, log.RequestType)
 	require.True(t, log.Stream)
 	require.True(t, log.OpenAIWSMode)
 	require.NoError(t, mock.ExpectationsWereMet())
 }
 
+func TestUsageLogRepositoryCreate_PersistsServiceTier(t *testing.T) {
+	db, mock := newSQLMock(t)
+	repo := &usageLogRepository{sql: db}
+
+	createdAt := time.Date(2025, 1, 2, 12, 0, 0, 0, time.UTC)
+	serviceTier := "priority"
+	log := &service.UsageLog{
+		UserID:      1,
+		APIKeyID:    2,
+		AccountID:   3,
+		RequestID:   "req-service-tier",
+		Model:       "gpt-5.4",
+		ServiceTier: &serviceTier,
+		CreatedAt:   createdAt,
+	}
+
+	mock.ExpectQuery("INSERT INTO usage_logs").
+		WithArgs(
+			log.UserID,
+			log.APIKeyID,
+			log.AccountID,
+			log.RequestID,
+			log.Model,
+			sqlmock.AnyArg(),
+			sqlmock.AnyArg(),
+			log.InputTokens,
+			log.OutputTokens,
+			log.CacheCreationTokens,
+			log.CacheReadTokens,
+			log.CacheCreation5mTokens,
+			log.CacheCreation1hTokens,
+			log.InputCost,
+			log.OutputCost,
+			log.CacheCreationCost,
+			log.CacheReadCost,
+			log.TotalCost,
+			log.ActualCost,
+			log.RateMultiplier,
+			log.AccountRateMultiplier,
+			log.BillingType,
+			int16(service.RequestTypeSync),
+			false,
+			false,
+			sqlmock.AnyArg(),
+			sqlmock.AnyArg(),
+			sqlmock.AnyArg(),
+			sqlmock.AnyArg(),
+			log.ImageCount,
+			sqlmock.AnyArg(),
+			sqlmock.AnyArg(),
+			serviceTier,
+			sqlmock.AnyArg(),
+			log.CacheTTLOverridden,
+			createdAt,
+		).
+		WillReturnRows(sqlmock.NewRows([]string{"id", "created_at"}).AddRow(int64(100), createdAt))
+
+	inserted, err := repo.Create(context.Background(), log)
+	require.NoError(t, err)
+	require.True(t, inserted)
+	require.NoError(t, mock.ExpectationsWereMet())
+}
+
 func TestUsageLogRepositoryListWithFiltersRequestTypePriority(t *testing.T) {
 	db, mock := newSQLMock(t)
 	repo := &usageLogRepository{sql: db}
@@ -280,11 +345,14 @@ func TestScanUsageLogRequestTypeAndLegacyFallback(t *testing.T) {
 			0,
 			sql.NullString{},
 			sql.NullString{},
+			sql.NullString{Valid: true, String: "priority"},
 			sql.NullString{},
 			false,
 			now,
 		}})
 		require.NoError(t, err)
+		require.NotNil(t, log.ServiceTier)
+		require.Equal(t, "priority", *log.ServiceTier)
 		require.Equal(t, service.RequestTypeWSV2, log.RequestType)
 		require.True(t, log.Stream)
 		require.True(t, log.OpenAIWSMode)
@@ -316,13 +384,53 @@ func TestScanUsageLogRequestTypeAndLegacyFallback(t *testing.T) {
 			0,
 			sql.NullString{},
 			sql.NullString{},
+			sql.NullString{Valid: true, String: "flex"},
 			sql.NullString{},
 			false,
 			now,
 		}})
 		require.NoError(t, err)
+		require.NotNil(t, log.ServiceTier)
+		require.Equal(t, "flex", *log.ServiceTier)
 		require.Equal(t, service.RequestTypeStream, log.RequestType)
 		require.True(t, log.Stream)
 		require.False(t, log.OpenAIWSMode)
 	})
+
+	t.Run("service_tier_is_scanned", func(t *testing.T) {
+		now := time.Now().UTC()
+		log, err := scanUsageLog(usageLogScannerStub{values: []any{
+			int64(3),
+			int64(12),
+			int64(22),
+			int64(32),
+			sql.NullString{Valid: true, String: "req-3"},
+			"gpt-5.4",
+			sql.NullInt64{},
+			sql.NullInt64{},
+			1, 2, 3, 4, 5, 6,
+			0.1, 0.2, 0.3, 0.4, 1.0, 0.9,
+			1.0,
+			sql.NullFloat64{},
+			int16(service.BillingTypeBalance),
+			int16(service.RequestTypeSync),
+			false,
+			false,
+			sql.NullInt64{},
+			sql.NullInt64{},
+			sql.NullString{},
+			sql.NullString{},
+			0,
+			sql.NullString{},
+			sql.NullString{},
+			sql.NullString{Valid: true, String: "priority"},
+			sql.NullString{},
+			false,
+			now,
+		}})
+		require.NoError(t, err)
+		require.NotNil(t, log.ServiceTier)
+		require.Equal(t, "priority", *log.ServiceTier)
+	})
+
 }