feat: add default proxy selection for new accounts

backend/internal/handler/admin/setting_handler.go

@@ -197,6 +197,7 @@ func (h *SettingHandler) GetSettings(c *gin.Context) {
 		TablePageSizeOptions:                   settings.TablePageSizeOptions,
 		CustomMenuItems:                        dto.ParseCustomMenuItems(settings.CustomMenuItems),
 		CustomEndpoints:                        dto.ParseCustomEndpoints(settings.CustomEndpoints),
+		DefaultProxyID:                         settings.DefaultProxyID,
 		DefaultConcurrency:                     settings.DefaultConcurrency,
 		DefaultBalance:                         settings.DefaultBalance,
 		RiskControlEnabled:                     settings.RiskControlEnabled,
@@ -442,6 +443,7 @@ type UpdateSettingsRequest struct {
 	TablePageSizeOptions        []int                 `json:"table_page_size_options"`
 	CustomMenuItems             *[]dto.CustomMenuItem `json:"custom_menu_items"`
 	CustomEndpoints             *[]dto.CustomEndpoint `json:"custom_endpoints"`
+	DefaultProxyID              *int64                `json:"default_proxy_id"`
 
 	// 默认配置
 	DefaultConcurrency                       int                               `json:"default_concurrency"`
@@ -1348,25 +1350,35 @@ func (h *SettingHandler) UpdateSettings(c *gin.Context) {
 		TablePageSizeOptions:             req.TablePageSizeOptions,
 		CustomMenuItems:                  customMenuJSON,
 		CustomEndpoints:                  customEndpointsJSON,
-		DefaultConcurrency:               req.DefaultConcurrency,
-		DefaultBalance:                   req.DefaultBalance,
-		AffiliateRebateRate:              affiliateRebateRate,
-		AffiliateRebateFreezeHours:       affiliateRebateFreezeHours,
-		AffiliateRebateDurationDays:      affiliateRebateDurationDays,
-		AffiliateRebatePerInviteeCap:     affiliateRebatePerInviteeCap,
-		DefaultUserRPMLimit:              req.DefaultUserRPMLimit,
-		DefaultSubscriptions:             defaultSubscriptions,
-		EnableModelFallback:              req.EnableModelFallback,
-		FallbackModelAnthropic:           req.FallbackModelAnthropic,
-		FallbackModelOpenAI:              req.FallbackModelOpenAI,
-		FallbackModelGemini:              req.FallbackModelGemini,
-		FallbackModelAntigravity:         req.FallbackModelAntigravity,
-		EnableIdentityPatch:              req.EnableIdentityPatch,
-		IdentityPatchPrompt:              req.IdentityPatchPrompt,
-		MinClaudeCodeVersion:             req.MinClaudeCodeVersion,
-		MaxClaudeCodeVersion:             req.MaxClaudeCodeVersion,
-		AllowUngroupedKeyScheduling:      req.AllowUngroupedKeyScheduling,
-		BackendModeEnabled:               req.BackendModeEnabled,
+		DefaultProxyID: func() *int64 {
+			if req.DefaultProxyID != nil {
+				if *req.DefaultProxyID <= 0 {
+					return nil
+				}
+				value := *req.DefaultProxyID
+				return &value
+			}
+			return previousSettings.DefaultProxyID
+		}(),
+		DefaultConcurrency:           req.DefaultConcurrency,
+		DefaultBalance:               req.DefaultBalance,
+		AffiliateRebateRate:          affiliateRebateRate,
+		AffiliateRebateFreezeHours:   affiliateRebateFreezeHours,
+		AffiliateRebateDurationDays:  affiliateRebateDurationDays,
+		AffiliateRebatePerInviteeCap: affiliateRebatePerInviteeCap,
+		DefaultUserRPMLimit:          req.DefaultUserRPMLimit,
+		DefaultSubscriptions:         defaultSubscriptions,
+		EnableModelFallback:          req.EnableModelFallback,
+		FallbackModelAnthropic:       req.FallbackModelAnthropic,
+		FallbackModelOpenAI:          req.FallbackModelOpenAI,
+		FallbackModelGemini:          req.FallbackModelGemini,
+		FallbackModelAntigravity:     req.FallbackModelAntigravity,
+		EnableIdentityPatch:          req.EnableIdentityPatch,
+		IdentityPatchPrompt:          req.IdentityPatchPrompt,
+		MinClaudeCodeVersion:         req.MinClaudeCodeVersion,
+		MaxClaudeCodeVersion:         req.MaxClaudeCodeVersion,
+		AllowUngroupedKeyScheduling:  req.AllowUngroupedKeyScheduling,
+		BackendModeEnabled:           req.BackendModeEnabled,
 		OpsMonitoringEnabled: func() bool {
 			if req.OpsMonitoringEnabled != nil {
 				return *req.OpsMonitoringEnabled
@@ -1720,6 +1732,7 @@ func (h *SettingHandler) UpdateSettings(c *gin.Context) {
 		TablePageSizeOptions:                   updatedSettings.TablePageSizeOptions,
 		CustomMenuItems:                        dto.ParseCustomMenuItems(updatedSettings.CustomMenuItems),
 		CustomEndpoints:                        dto.ParseCustomEndpoints(updatedSettings.CustomEndpoints),
+		DefaultProxyID:                         updatedSettings.DefaultProxyID,
 		DefaultConcurrency:                     updatedSettings.DefaultConcurrency,
 		DefaultBalance:                         updatedSettings.DefaultBalance,
 		AffiliateRebateRate:                    updatedSettings.AffiliateRebateRate,
@@ -2047,6 +2060,9 @@ func diffSettings(before *service.SystemSettings, after *service.SystemSettings,
 	if before.HideCcsImportButton != after.HideCcsImportButton {
 		changed = append(changed, "hide_ccs_import_button")
 	}
+	if !equalInt64Ptr(before.DefaultProxyID, after.DefaultProxyID) {
+		changed = append(changed, "default_proxy_id")
+	}
 	if before.DefaultConcurrency != after.DefaultConcurrency {
 		changed = append(changed, "default_concurrency")
 	}
@@ -2298,6 +2314,13 @@ func defaultSubscriptionsValueOrDefault(input *[]dto.DefaultSubscriptionSetting,
 	return result
 }
 
+func equalInt64Ptr(a, b *int64) bool {
+	if a == nil || b == nil {
+		return a == nil && b == nil
+	}
+	return *a == *b
+}
+
 func systemSettingsResponseData(settings dto.SystemSettings, authSourceDefaults *service.AuthSourceDefaultSettings) map[string]any {
 	data := make(map[string]any)
 	raw, err := json.Marshal(settings)

backend/internal/handler/dto/settings.go

@@ -121,6 +121,7 @@ type SystemSettings struct {
 	TablePageSizeOptions        []int            `json:"table_page_size_options"`
 	CustomMenuItems             []CustomMenuItem `json:"custom_menu_items"`
 	CustomEndpoints             []CustomEndpoint `json:"custom_endpoints"`
+	DefaultProxyID              *int64           `json:"default_proxy_id"`
 
 	DefaultConcurrency           int                          `json:"default_concurrency"`
 	DefaultBalance               float64                      `json:"default_balance"`

backend/internal/repository/billing_cache.go

@@ -33,7 +33,7 @@ func jitteredTTL() time.Duration {
 	if billingCacheJitter <= 0 {
 		return billingCacheTTL
 	}
-	jitter := time.Duration(rand.IntN(int(billingCacheJitter)))
+	jitter := time.Duration(rand.Int64N(int64(billingCacheJitter)))
 	return billingCacheTTL - jitter
 }
 

backend/internal/service/domain_constants.go

@@ -206,6 +206,7 @@ const (
 	SettingKeyTablePageSizeOptions        = "table_page_size_options"       // 表格可选每页条数（JSON 数组）
 	SettingKeyCustomMenuItems             = "custom_menu_items"             // 自定义菜单项（JSON 数组）
 	SettingKeyCustomEndpoints             = "custom_endpoints"              // 自定义端点列表（JSON 数组）
+	SettingKeyDefaultProxyID              = "default_proxy_id"              // 添加账号时默认选中的代理 ID
 
 	// 默认配置
 	SettingKeyDefaultConcurrency   = "default_concurrency"    // 新用户默认并发量

backend/internal/service/gateway_request_test.go

@@ -981,7 +981,7 @@ func TestParseGatewayRequest_MaxTokensBoundary(t *testing.T) {
 		{
 			name:          "超大值不 panic",
 			body:          `{"max_tokens":9999999999999999}`,
-			wantMaxTokens: 10000000000000000, // float64 精度导致 9999999999999999 → 1e16
+			wantMaxTokens: 0, // 超出 math.MaxInt 时应被忽略，但不能 panic
 		},
 		{
 			name:          "null 值被忽略",

backend/internal/service/gemini_oauth_service.go

@@ -39,8 +39,8 @@ const (
 )
 
 const (
-	GB = 1024 * 1024 * 1024
-	TB = 1024 * GB
+	GB int64 = 1024 * 1024 * 1024
+	TB int64 = 1024 * GB
 
 	StorageTierUnlimited = 100 * TB // 100TB
 	StorageTierAIPremium = 2 * TB   // 2TB

backend/internal/service/setting_service.go

@@ -1504,6 +1504,11 @@ func (s *SettingService) buildSystemSettingsUpdates(ctx context.Context, setting
 	updates[SettingKeyTablePageSizeOptions] = string(tablePageSizeOptionsJSON)
 	updates[SettingKeyCustomMenuItems] = settings.CustomMenuItems
 	updates[SettingKeyCustomEndpoints] = settings.CustomEndpoints
+	if settings.DefaultProxyID != nil && *settings.DefaultProxyID > 0 {
+		updates[SettingKeyDefaultProxyID] = strconv.FormatInt(*settings.DefaultProxyID, 10)
+	} else {
+		updates[SettingKeyDefaultProxyID] = ""
+	}
 
 	// 默认配置
 	updates[SettingKeyDefaultConcurrency] = strconv.Itoa(settings.DefaultConcurrency)
@@ -2233,6 +2238,7 @@ func (s *SettingService) InitializeDefaultSettings(ctx context.Context) error {
 		SettingKeyTablePageSizeOptions:                     "[10,20,50,100]",
 		SettingKeyCustomMenuItems:                          "[]",
 		SettingKeyCustomEndpoints:                          "[]",
+		SettingKeyDefaultProxyID:                           "",
 		SettingKeyWeChatConnectEnabled:                     "false",
 		SettingKeyWeChatConnectAppID:                       "",
 		SettingKeyWeChatConnectAppSecret:                   "",
@@ -2412,6 +2418,9 @@ func (s *SettingService) parseSettings(settings map[string]string) *SystemSettin
 		CustomEndpoints:                  settings[SettingKeyCustomEndpoints],
 		BackendModeEnabled:               settings[SettingKeyBackendModeEnabled] == "true",
 	}
+	if defaultProxyID, err := strconv.ParseInt(strings.TrimSpace(settings[SettingKeyDefaultProxyID]), 10, 64); err == nil && defaultProxyID > 0 {
+		result.DefaultProxyID = &defaultProxyID
+	}
 	result.TableDefaultPageSize, result.TablePageSizeOptions = parseTablePreferences(
 		settings[SettingKeyTableDefaultPageSize],
 		settings[SettingKeyTablePageSizeOptions],

backend/internal/service/setting_service_update_test.go

@@ -224,6 +224,39 @@ func TestSettingService_UpdateSettings_TablePreferences(t *testing.T) {
 	require.Equal(t, "[20,100]", repo.updates[SettingKeyTablePageSizeOptions])
 }
 
+func TestSettingService_UpdateSettings_DefaultProxyID(t *testing.T) {
+	repo := &settingUpdateRepoStub{}
+	svc := NewSettingService(repo, &config.Config{})
+	defaultProxyID := int64(42)
+
+	err := svc.UpdateSettings(context.Background(), &SystemSettings{
+		DefaultProxyID: &defaultProxyID,
+	})
+	require.NoError(t, err)
+	require.Equal(t, "42", repo.updates[SettingKeyDefaultProxyID])
+
+	err = svc.UpdateSettings(context.Background(), &SystemSettings{
+		DefaultProxyID: nil,
+	})
+	require.NoError(t, err)
+	require.Equal(t, "", repo.updates[SettingKeyDefaultProxyID])
+}
+
+func TestSettingService_ParseSettings_DefaultProxyID(t *testing.T) {
+	svc := NewSettingService(&settingUpdateRepoStub{}, &config.Config{})
+
+	got := svc.parseSettings(map[string]string{
+		SettingKeyDefaultProxyID: "88",
+	})
+	require.NotNil(t, got.DefaultProxyID)
+	require.EqualValues(t, 88, *got.DefaultProxyID)
+
+	got = svc.parseSettings(map[string]string{
+		SettingKeyDefaultProxyID: "",
+	})
+	require.Nil(t, got.DefaultProxyID)
+}
+
 func TestSettingService_UpdateSettings_PaymentVisibleMethodsAndAdvancedScheduler(t *testing.T) {
 	repo := &settingUpdateRepoStub{}
 	svc := NewSettingService(repo, &config.Config{})

backend/internal/service/settings_view.go

@@ -121,6 +121,7 @@ type SystemSettings struct {
 	TablePageSizeOptions        []int
 	CustomMenuItems             string // JSON array of custom menu items
 	CustomEndpoints             string // JSON array of custom endpoints
+	DefaultProxyID              *int64
 
 	DefaultConcurrency           int
 	DefaultBalance               float64

frontend/src/api/admin/settings.ts

@@ -377,6 +377,7 @@ export interface SystemSettings {
   backend_mode_enabled: boolean;
   custom_menu_items: CustomMenuItem[];
   custom_endpoints: CustomEndpoint[];
+  default_proxy_id?: number | null;
   // SMTP settings
   smtp_host: string;
   smtp_port: number;
@@ -593,6 +594,7 @@ export interface UpdateSettingsRequest {
   backend_mode_enabled?: boolean;
   custom_menu_items?: CustomMenuItem[];
   custom_endpoints?: CustomEndpoint[];
+  default_proxy_id?: number | null;
   smtp_host?: string;
   smtp_port?: number;
   smtp_username?: string;