fix: resolve CI failures — gofmt, unused functions, test parameter mismatches

- gofmt: user.go, config_test.go, group_handler.go, smart_retry_test.go
- Remove unused: mergeGroupIDs, resolveProxyURL, "time" import
- Fix api_contract_test.go: remove extra Sora args from NewAdminService,
  NewSettingHandler, NewAccountHandler; remove Sora field expectations
- Fix account_test_service_openai_test.go: restore test helpers

backend/internal/handler/admin/user_handler.go

@@ -34,13 +34,13 @@ func NewUserHandler(adminService service.AdminService, concurrencyService *servi
 
 // CreateUserRequest represents admin create user request
 type CreateUserRequest struct {
-	Email                 string  `json:"email" binding:"required,email"`
-	Password              string  `json:"password" binding:"required,min=6"`
-	Username              string  `json:"username"`
-	Notes                 string  `json:"notes"`
-	Balance               float64 `json:"balance"`
-	Concurrency           int     `json:"concurrency"`
-	AllowedGroups         []int64 `json:"allowed_groups"`
+	Email         string  `json:"email" binding:"required,email"`
+	Password      string  `json:"password" binding:"required,min=6"`
+	Username      string  `json:"username"`
+	Notes         string  `json:"notes"`
+	Balance       float64 `json:"balance"`
+	Concurrency   int     `json:"concurrency"`
+	AllowedGroups []int64 `json:"allowed_groups"`
 }
 
 // UpdateUserRequest represents admin update user request
@@ -56,7 +56,7 @@ type UpdateUserRequest struct {
 	AllowedGroups *[]int64 `json:"allowed_groups"`
 	// GroupRates 用户专属分组倍率配置
 	// map[groupID]*rate，nil 表示删除该分组的专属倍率
-	GroupRates            map[int64]*float64 `json:"group_rates"`
+	GroupRates map[int64]*float64 `json:"group_rates"`
 }
 
 // UpdateBalanceRequest represents balance update request
@@ -180,13 +180,13 @@ func (h *UserHandler) Create(c *gin.Context) {
 	}
 
 	user, err := h.adminService.CreateUser(c.Request.Context(), &service.CreateUserInput{
-		Email:                 req.Email,
-		Password:              req.Password,
-		Username:              req.Username,
-		Notes:                 req.Notes,
-		Balance:               req.Balance,
-		Concurrency:           req.Concurrency,
-		AllowedGroups:         req.AllowedGroups,
+		Email:         req.Email,
+		Password:      req.Password,
+		Username:      req.Username,
+		Notes:         req.Notes,
+		Balance:       req.Balance,
+		Concurrency:   req.Concurrency,
+		AllowedGroups: req.AllowedGroups,
 	})
 	if err != nil {
 		response.ErrorFrom(c, err)
@@ -213,15 +213,15 @@ func (h *UserHandler) Update(c *gin.Context) {
 
 	// 使用指针类型直接传递，nil 表示未提供该字段
 	user, err := h.adminService.UpdateUser(c.Request.Context(), userID, &service.UpdateUserInput{
-		Email:                 req.Email,
-		Password:              req.Password,
-		Username:              req.Username,
-		Notes:                 req.Notes,
-		Balance:               req.Balance,
-		Concurrency:           req.Concurrency,
-		Status:                req.Status,
-		AllowedGroups:         req.AllowedGroups,
-		GroupRates:            req.GroupRates,
+		Email:         req.Email,
+		Password:      req.Password,
+		Username:      req.Username,
+		Notes:         req.Notes,
+		Balance:       req.Balance,
+		Concurrency:   req.Concurrency,
+		Status:        req.Status,
+		AllowedGroups: req.AllowedGroups,
+		GroupRates:    req.GroupRates,
 	})
 	if err != nil {
 		response.ErrorFrom(c, err)