feat: 反重力（Antigravity）增强、Failover 重构及新模型支持

backend/internal/config/config.go

@@ -1158,6 +1158,7 @@ func setDefaults() {
 	viper.SetDefault("gateway.force_codex_cli", false)
 	viper.SetDefault("gateway.openai_passthrough_allow_timeout_headers", false)
 	viper.SetDefault("gateway.antigravity_fallback_cooldown_minutes", 1)
+	viper.SetDefault("gateway.antigravity_extra_retries", 10)
 	viper.SetDefault("gateway.max_body_size", int64(100*1024*1024))
 	viper.SetDefault("gateway.upstream_response_read_max_bytes", int64(8*1024*1024))
 	viper.SetDefault("gateway.proxy_probe_response_read_max_bytes", int64(1024*1024))

backend/internal/domain/constants.go

@@ -74,6 +74,7 @@ var DefaultAntigravityModelMapping = map[string]string{
 	"claude-opus-4-6-thinking":   "claude-opus-4-6-thinking", // 官方模型
 	"claude-opus-4-6":            "claude-opus-4-6-thinking", // 简称映射
 	"claude-opus-4-5-thinking":   "claude-opus-4-6-thinking", // 迁移旧模型
+	"claude-sonnet-4-6":          "claude-sonnet-4-6",
 	"claude-sonnet-4-5":          "claude-sonnet-4-5",
 	"claude-sonnet-4-5-thinking": "claude-sonnet-4-5-thinking",
 	// Claude 详细版本 ID 映射
@@ -89,16 +90,18 @@ var DefaultAntigravityModelMapping = map[string]string{
 	"gemini-2.5-pro":            "gemini-2.5-pro",
 	// Gemini 3 白名单
 	"gemini-3-flash":     "gemini-3-flash",
-	"gemini-3-pro-high":  "gemini-3.1-pro-high",
-	"gemini-3-pro-low":   "gemini-3.1-pro-low",
+	"gemini-3-pro-high":  "gemini-3-pro-high",
+	"gemini-3-pro-low":   "gemini-3-pro-low",
 	"gemini-3-pro-image": "gemini-3-pro-image",
-	// Gemini 3.1 透传
-	"gemini-3.1-pro-high": "gemini-3.1-pro-high",
-	"gemini-3.1-pro-low":  "gemini-3.1-pro-low",
 	// Gemini 3 preview 映射
 	"gemini-3-flash-preview":     "gemini-3-flash",
-	"gemini-3-pro-preview":       "gemini-3.1-pro-high",
+	"gemini-3-pro-preview":       "gemini-3-pro-high",
 	"gemini-3-pro-image-preview": "gemini-3-pro-image",
+	// Gemini 3.1 白名单
+	"gemini-3.1-pro-high": "gemini-3.1-pro-high",
+	"gemini-3.1-pro-low":  "gemini-3.1-pro-low",
+	// Gemini 3.1 preview 映射
+	"gemini-3.1-pro-preview": "gemini-3.1-pro-high",
 	// 其他官方模型
 	"gpt-oss-120b-medium":    "gpt-oss-120b-medium",
 	"tab_flash_lite_preview": "tab_flash_lite_preview",

backend/internal/handler/admin/account_handler.go

@@ -139,6 +139,13 @@ type BulkUpdateAccountsRequest struct {
 	ConfirmMixedChannelRisk *bool          `json:"confirm_mixed_channel_risk"` // 用户确认混合渠道风险
 }
 
+// CheckMixedChannelRequest represents check mixed channel risk request
+type CheckMixedChannelRequest struct {
+	Platform  string  `json:"platform" binding:"required"`
+	GroupIDs  []int64 `json:"group_ids"`
+	AccountID *int64  `json:"account_id"`
+}
+
 // AccountWithConcurrency extends Account with real-time concurrency info
 type AccountWithConcurrency struct {
 	*dto.Account
@@ -389,6 +396,50 @@ func (h *AccountHandler) GetByID(c *gin.Context) {
 	response.Success(c, h.buildAccountResponseWithRuntime(c.Request.Context(), account))
 }
 
+// CheckMixedChannel handles checking mixed channel risk for account-group binding.
+// POST /api/v1/admin/accounts/check-mixed-channel
+func (h *AccountHandler) CheckMixedChannel(c *gin.Context) {
+	var req CheckMixedChannelRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, "Invalid request: "+err.Error())
+		return
+	}
+
+	if len(req.GroupIDs) == 0 {
+		response.Success(c, gin.H{"has_risk": false})
+		return
+	}
+
+	accountID := int64(0)
+	if req.AccountID != nil {
+		accountID = *req.AccountID
+	}
+
+	err := h.adminService.CheckMixedChannelRisk(c.Request.Context(), accountID, req.Platform, req.GroupIDs)
+	if err != nil {
+		var mixedErr *service.MixedChannelError
+		if errors.As(err, &mixedErr) {
+			response.Success(c, gin.H{
+				"has_risk": true,
+				"error":    "mixed_channel_warning",
+				"message":  mixedErr.Error(),
+				"details": gin.H{
+					"group_id":         mixedErr.GroupID,
+					"group_name":       mixedErr.GroupName,
+					"current_platform": mixedErr.CurrentPlatform,
+					"other_platform":   mixedErr.OtherPlatform,
+				},
+			})
+			return
+		}
+
+		response.ErrorFrom(c, err)
+		return
+	}
+
+	response.Success(c, gin.H{"has_risk": false})
+}
+
 // Create handles creating a new account
 // POST /api/v1/admin/accounts
 func (h *AccountHandler) Create(c *gin.Context) {
@@ -431,17 +482,10 @@ func (h *AccountHandler) Create(c *gin.Context) {
 		// 检查是否为混合渠道错误
 		var mixedErr *service.MixedChannelError
 		if errors.As(err, &mixedErr) {
-			// 返回特殊错误码要求确认
+			// 创建接口仅返回最小必要字段，详细信息由专门检查接口提供
 			c.JSON(409, gin.H{
 				"error":   "mixed_channel_warning",
 				"message": mixedErr.Error(),
-				"details": gin.H{
-					"group_id":         mixedErr.GroupID,
-					"group_name":       mixedErr.GroupName,
-					"current_platform": mixedErr.CurrentPlatform,
-					"other_platform":   mixedErr.OtherPlatform,
-				},
-				"require_confirmation": true,
 			})
 			return
 		}
@@ -501,17 +545,10 @@ func (h *AccountHandler) Update(c *gin.Context) {
 		// 检查是否为混合渠道错误
 		var mixedErr *service.MixedChannelError
 		if errors.As(err, &mixedErr) {
-			// 返回特殊错误码要求确认
+			// 更新接口仅返回最小必要字段，详细信息由专门检查接口提供
 			c.JSON(409, gin.H{
 				"error":   "mixed_channel_warning",
 				"message": mixedErr.Error(),
-				"details": gin.H{
-					"group_id":         mixedErr.GroupID,
-					"group_name":       mixedErr.GroupName,
-					"current_platform": mixedErr.CurrentPlatform,
-					"other_platform":   mixedErr.OtherPlatform,
-				},
-				"require_confirmation": true,
 			})
 			return
 		}

backend/internal/handler/admin/account_handler_mixed_channel_test.go

@@ -0,0 +1,147 @@
+package admin
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/Wei-Shaw/sub2api/internal/service"
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/require"
+)
+
+func setupAccountMixedChannelRouter(adminSvc *stubAdminService) *gin.Engine {
+	gin.SetMode(gin.TestMode)
+	router := gin.New()
+	accountHandler := NewAccountHandler(adminSvc, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil)
+	router.POST("/api/v1/admin/accounts/check-mixed-channel", accountHandler.CheckMixedChannel)
+	router.POST("/api/v1/admin/accounts", accountHandler.Create)
+	router.PUT("/api/v1/admin/accounts/:id", accountHandler.Update)
+	return router
+}
+
+func TestAccountHandlerCheckMixedChannelNoRisk(t *testing.T) {
+	adminSvc := newStubAdminService()
+	router := setupAccountMixedChannelRouter(adminSvc)
+
+	body, _ := json.Marshal(map[string]any{
+		"platform":  "antigravity",
+		"group_ids": []int64{27},
+	})
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodPost, "/api/v1/admin/accounts/check-mixed-channel", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	router.ServeHTTP(rec, req)
+
+	require.Equal(t, http.StatusOK, rec.Code)
+	var resp map[string]any
+	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &resp))
+	require.Equal(t, float64(0), resp["code"])
+	data, ok := resp["data"].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, false, data["has_risk"])
+	require.Equal(t, int64(0), adminSvc.lastMixedCheck.accountID)
+	require.Equal(t, "antigravity", adminSvc.lastMixedCheck.platform)
+	require.Equal(t, []int64{27}, adminSvc.lastMixedCheck.groupIDs)
+}
+
+func TestAccountHandlerCheckMixedChannelWithRisk(t *testing.T) {
+	adminSvc := newStubAdminService()
+	adminSvc.checkMixedErr = &service.MixedChannelError{
+		GroupID:         27,
+		GroupName:       "claude-max",
+		CurrentPlatform: "Antigravity",
+		OtherPlatform:   "Anthropic",
+	}
+	router := setupAccountMixedChannelRouter(adminSvc)
+
+	body, _ := json.Marshal(map[string]any{
+		"platform":   "antigravity",
+		"group_ids":  []int64{27},
+		"account_id": 99,
+	})
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodPost, "/api/v1/admin/accounts/check-mixed-channel", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	router.ServeHTTP(rec, req)
+
+	require.Equal(t, http.StatusOK, rec.Code)
+	var resp map[string]any
+	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &resp))
+	require.Equal(t, float64(0), resp["code"])
+	data, ok := resp["data"].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, true, data["has_risk"])
+	require.Equal(t, "mixed_channel_warning", data["error"])
+	details, ok := data["details"].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, float64(27), details["group_id"])
+	require.Equal(t, "claude-max", details["group_name"])
+	require.Equal(t, "Antigravity", details["current_platform"])
+	require.Equal(t, "Anthropic", details["other_platform"])
+	require.Equal(t, int64(99), adminSvc.lastMixedCheck.accountID)
+}
+
+func TestAccountHandlerCreateMixedChannelConflictSimplifiedResponse(t *testing.T) {
+	adminSvc := newStubAdminService()
+	adminSvc.createAccountErr = &service.MixedChannelError{
+		GroupID:         27,
+		GroupName:       "claude-max",
+		CurrentPlatform: "Antigravity",
+		OtherPlatform:   "Anthropic",
+	}
+	router := setupAccountMixedChannelRouter(adminSvc)
+
+	body, _ := json.Marshal(map[string]any{
+		"name":        "ag-oauth-1",
+		"platform":    "antigravity",
+		"type":        "oauth",
+		"credentials": map[string]any{"refresh_token": "rt"},
+		"group_ids":   []int64{27},
+	})
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodPost, "/api/v1/admin/accounts", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	router.ServeHTTP(rec, req)
+
+	require.Equal(t, http.StatusConflict, rec.Code)
+	var resp map[string]any
+	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &resp))
+	require.Equal(t, "mixed_channel_warning", resp["error"])
+	require.Contains(t, resp["message"], "mixed_channel_warning")
+	_, hasDetails := resp["details"]
+	_, hasRequireConfirmation := resp["require_confirmation"]
+	require.False(t, hasDetails)
+	require.False(t, hasRequireConfirmation)
+}
+
+func TestAccountHandlerUpdateMixedChannelConflictSimplifiedResponse(t *testing.T) {
+	adminSvc := newStubAdminService()
+	adminSvc.updateAccountErr = &service.MixedChannelError{
+		GroupID:         27,
+		GroupName:       "claude-max",
+		CurrentPlatform: "Antigravity",
+		OtherPlatform:   "Anthropic",
+	}
+	router := setupAccountMixedChannelRouter(adminSvc)
+
+	body, _ := json.Marshal(map[string]any{
+		"group_ids": []int64{27},
+	})
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodPut, "/api/v1/admin/accounts/3", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	router.ServeHTTP(rec, req)
+
+	require.Equal(t, http.StatusConflict, rec.Code)
+	var resp map[string]any
+	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &resp))
+	require.Equal(t, "mixed_channel_warning", resp["error"])
+	require.Contains(t, resp["message"], "mixed_channel_warning")
+	_, hasDetails := resp["details"]
+	_, hasRequireConfirmation := resp["require_confirmation"]
+	require.False(t, hasDetails)
+	require.False(t, hasRequireConfirmation)
+}

backend/internal/handler/admin/admin_service_stub_test.go

@@ -10,19 +10,27 @@ import (
 )
 
 type stubAdminService struct {
-	users           []service.User
-	apiKeys         []service.APIKey
-	groups          []service.Group
-	accounts        []service.Account
-	proxies         []service.Proxy
-	proxyCounts     []service.ProxyWithAccountCount
-	redeems         []service.RedeemCode
-	createdAccounts []*service.CreateAccountInput
-	createdProxies  []*service.CreateProxyInput
-	updatedProxyIDs []int64
-	updatedProxies  []*service.UpdateProxyInput
-	testedProxyIDs  []int64
-	mu              sync.Mutex
+	users            []service.User
+	apiKeys          []service.APIKey
+	groups           []service.Group
+	accounts         []service.Account
+	proxies          []service.Proxy
+	proxyCounts      []service.ProxyWithAccountCount
+	redeems          []service.RedeemCode
+	createdAccounts  []*service.CreateAccountInput
+	createdProxies   []*service.CreateProxyInput
+	updatedProxyIDs  []int64
+	updatedProxies   []*service.UpdateProxyInput
+	testedProxyIDs   []int64
+	createAccountErr error
+	updateAccountErr error
+	checkMixedErr    error
+	lastMixedCheck   struct {
+		accountID int64
+		platform  string
+		groupIDs  []int64
+	}
+	mu sync.Mutex
 }
 
 func newStubAdminService() *stubAdminService {
@@ -188,11 +196,17 @@ func (s *stubAdminService) CreateAccount(ctx context.Context, input *service.Cre
 	s.mu.Lock()
 	s.createdAccounts = append(s.createdAccounts, input)
 	s.mu.Unlock()
+	if s.createAccountErr != nil {
+		return nil, s.createAccountErr
+	}
 	account := service.Account{ID: 300, Name: input.Name, Status: service.StatusActive}
 	return &account, nil
 }
 
 func (s *stubAdminService) UpdateAccount(ctx context.Context, id int64, input *service.UpdateAccountInput) (*service.Account, error) {
+	if s.updateAccountErr != nil {
+		return nil, s.updateAccountErr
+	}
 	account := service.Account{ID: id, Name: input.Name, Status: service.StatusActive}
 	return &account, nil
 }
@@ -224,6 +238,13 @@ func (s *stubAdminService) BulkUpdateAccounts(ctx context.Context, input *servic
 	return &service.BulkUpdateAccountsResult{Success: 1, Failed: 0, SuccessIDs: []int64{1}}, nil
 }
 
+func (s *stubAdminService) CheckMixedChannelRisk(ctx context.Context, currentAccountID int64, currentAccountPlatform string, groupIDs []int64) error {
+	s.lastMixedCheck.accountID = currentAccountID
+	s.lastMixedCheck.platform = currentAccountPlatform
+	s.lastMixedCheck.groupIDs = append([]int64(nil), groupIDs...)
+	return s.checkMixedErr
+}
+
 func (s *stubAdminService) ListProxies(ctx context.Context, page, pageSize int, protocol, status, search string) ([]service.Proxy, int64, error) {
 	search = strings.TrimSpace(strings.ToLower(search))
 	filtered := make([]service.Proxy, 0, len(s.proxies))