取消游客模式，强制登录后使用

backend/internal/handlers/admin.go

@@ -20,9 +20,9 @@ type AdminHandler struct {
 func allowedRolesForCreation(actor models.RoleName) []models.RoleName {
 	switch actor {
 	case models.RoleSystemAdmin:
-		return []models.RoleName{models.RoleAdmin, models.RoleUser, models.RoleGuest}
+		return []models.RoleName{models.RoleAdmin, models.RoleUser}
 	case models.RoleAdmin:
-		return []models.RoleName{models.RoleUser, models.RoleGuest}
+		return []models.RoleName{models.RoleUser}
 	default:
 		return nil
 	}

backend/internal/handlers/auth.go

@@ -153,13 +153,6 @@ func (h *AuthHandler) Logout(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"message": "登出成功"})
 }
 
-func (h *AuthHandler) PublicInfo(c *gin.Context) {
-	c.JSON(http.StatusOK, gin.H{
-		"message":       "欢迎访问 A股工具公开信息",
-		"guest_allowed": true,
-	})
-}
-
 func hashPassword(password string) (string, error) {
 	bytes, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
 	return string(bytes), err