fix(user): 普通用户接口不返回备注

- 用户侧 dto.User 移除 notes 字段，避免泄露管理员备注\n- 新增 dto.AdminUser 并调整 /admin/users 系列接口使用\n- 前端拆分 User/AdminUser，管理端用户页面使用 AdminUser\n- 更新契约测试：/api/v1/auth/me 响应不包含 notes

backend/internal/handler/admin/user_handler.go

@@ -84,9 +84,9 @@ func (h *UserHandler) List(c *gin.Context) {
 		return
 	}
 
-	out := make([]dto.User, 0, len(users))
+	out := make([]dto.AdminUser, 0, len(users))
 	for i := range users {
-		out = append(out, *dto.UserFromService(&users[i]))
+		out = append(out, *dto.UserFromServiceAdmin(&users[i]))
 	}
 	response.Paginated(c, out, total, page, pageSize)
 }
@@ -129,7 +129,7 @@ func (h *UserHandler) GetByID(c *gin.Context) {
 		return
 	}
 
-	response.Success(c, dto.UserFromService(user))
+	response.Success(c, dto.UserFromServiceAdmin(user))
 }
 
 // Create handles creating a new user
@@ -155,7 +155,7 @@ func (h *UserHandler) Create(c *gin.Context) {
 		return
 	}
 
-	response.Success(c, dto.UserFromService(user))
+	response.Success(c, dto.UserFromServiceAdmin(user))
 }
 
 // Update handles updating a user
@@ -189,7 +189,7 @@ func (h *UserHandler) Update(c *gin.Context) {
 		return
 	}
 
-	response.Success(c, dto.UserFromService(user))
+	response.Success(c, dto.UserFromServiceAdmin(user))
 }
 
 // Delete handles deleting a user
@@ -231,7 +231,7 @@ func (h *UserHandler) UpdateBalance(c *gin.Context) {
 		return
 	}
 
-	response.Success(c, dto.UserFromService(user))
+	response.Success(c, dto.UserFromServiceAdmin(user))
 }
 
 // GetUserAPIKeys handles getting user's API keys

backend/internal/handler/dto/mappers.go

@@ -15,7 +15,6 @@ func UserFromServiceShallow(u *service.User) *User {
 		ID:            u.ID,
 		Email:         u.Email,
 		Username:      u.Username,
-		Notes:         u.Notes,
 		Role:          u.Role,
 		Balance:       u.Balance,
 		Concurrency:   u.Concurrency,
@@ -48,6 +47,22 @@ func UserFromService(u *service.User) *User {
 	return out
 }
 
+// UserFromServiceAdmin converts a service User to DTO for admin users.
+// It includes notes - user-facing endpoints must not use this.
+func UserFromServiceAdmin(u *service.User) *AdminUser {
+	if u == nil {
+		return nil
+	}
+	base := UserFromService(u)
+	if base == nil {
+		return nil
+	}
+	return &AdminUser{
+		User:  *base,
+		Notes: u.Notes,
+	}
+}
+
 func APIKeyFromService(k *service.APIKey) *APIKey {
 	if k == nil {
 		return nil

backend/internal/handler/dto/types.go

@@ -6,7 +6,6 @@ type User struct {
 	ID            int64     `json:"id"`
 	Email         string    `json:"email"`
 	Username      string    `json:"username"`
-	Notes         string    `json:"notes"`
 	Role          string    `json:"role"`
 	Balance       float64   `json:"balance"`
 	Concurrency   int       `json:"concurrency"`
@@ -19,6 +18,14 @@ type User struct {
 	Subscriptions []UserSubscription `json:"subscriptions,omitempty"`
 }
 
+// AdminUser 是管理员接口使用的 user DTO（包含敏感/内部字段）。
+// 注意：普通用户接口不得返回 notes 等管理员备注信息。
+type AdminUser struct {
+	User
+
+	Notes string `json:"notes"`
+}
+
 type APIKey struct {
 	ID          int64     `json:"id"`
 	UserID      int64     `json:"user_id"`

backend/internal/handler/user_handler.go

@@ -47,9 +47,6 @@ func (h *UserHandler) GetProfile(c *gin.Context) {
 		return
 	}
 
-	// 清空notes字段，普通用户不应看到备注
-	userData.Notes = ""
-
 	response.Success(c, dto.UserFromService(userData))
 }
 
@@ -105,8 +102,5 @@ func (h *UserHandler) UpdateProfile(c *gin.Context) {
 		return
 	}
 
-	// 清空notes字段，普通用户不应看到备注
-	updatedUser.Notes = ""
-
 	response.Success(c, dto.UserFromService(updatedUser))
 }

backend/internal/server/api_contract_test.go

@@ -51,7 +51,6 @@ func TestAPIContracts(t *testing.T) {
 					"id": 1,
 					"email": "alice@example.com",
 					"username": "alice",
-					"notes": "hello",
 					"role": "user",
 					"balance": 12.5,
 					"concurrency": 5,