fix: K8s集群编辑保存失败+凭据覆盖+去掉Kubectl死按钮

问题:
1. UpdateCluster 用 CreateK8sClusterRequest (code binding:"required"),
   编辑时不传 code → 校验失败 400 → 保存不成功
2. Token/KubeConfig json:"-" 不序列化, 编辑时拿不到原值,
   提交空字符串覆盖真实凭据
3. 操作菜单 Kubectl 是死按钮

修复:
- UpdateCluster 改用 map[string]interface{} 接收, 逐字段更新,
  空值不覆盖 (防止凭据清空)
- 新增 GET /:id/detail 返回 has_token/has_kube_config 脱敏标记
- 编辑弹框拉取详情 API 回填, Token/KubeConfig 留空显示 '已配置' 提示
- 去掉 Kubectl 死按钮, 保留 详情/配置/删除 三项

backend/internal/api/handlers/k8s.go

@@ -145,7 +145,8 @@ func (h *K8sHandler) CreateCluster(c *gin.Context) {
 func (h *K8sHandler) UpdateCluster(c *gin.Context) {
 	id, _ := strconv.Atoi(c.Param("id"))
 
-	var req models.CreateK8sClusterRequest
+	// 用 map 接收，避免 binding:"required" 校验 // Logan.Li
+	var req map[string]interface{}
 	if err := c.ShouldBindJSON(&req); err != nil {
 		c.JSON(http.StatusBadRequest, models.Response{
 			Code:    400,
@@ -163,15 +164,39 @@ func (h *K8sHandler) UpdateCluster(c *gin.Context) {
 		return
 	}
 
-	updates := map[string]interface{}{
-		"name":        req.Name,
-		"version":     req.Version,
-		"config_type": req.ConfigType,
-		"api_server":  req.APIServer,
-		"api_endpoint": req.APIServer,
-		"token":       req.Token,
-		"kube_config": req.KubeConfig,
-		"description": req.Description,
+	// 逐字段更新：空值不覆盖原值（防止凭据被清空） // Logan.Li
+	updates := map[string]interface{}{}
+	if v, ok := req["name"]; ok && v != nil && v != "" {
+		updates["name"] = v
+	}
+	if v, ok := req["version"]; ok {
+		updates["version"] = v
+	}
+	if v, ok := req["description"]; ok {
+		updates["description"] = v
+	}
+	if v, ok := req["config_type"]; ok {
+		updates["config_type"] = v
+	}
+	if v, ok := req["api_server"]; ok && v != nil && v != "" {
+		updates["api_server"] = v
+		updates["api_endpoint"] = v
+	}
+	// Token / KubeConfig：空值不覆盖（前端编辑时可能拿不到原值）
+	if v, ok := req["token"]; ok && v != nil && v != "" {
+		updates["token"] = v
+	}
+	if v, ok := req["kube_config"]; ok && v != nil && v != "" {
+		updates["kube_config"] = v
+	}
+
+	if len(updates) == 0 {
+		c.JSON(http.StatusOK, models.Response{
+			Code:    200,
+			Message: "无更新内容",
+			Data:    cluster,
+		})
+		return
 	}
 
 	if err := h.db.Model(&cluster).Updates(updates).Error; err != nil {
@@ -191,6 +216,44 @@ func (h *K8sHandler) UpdateCluster(c *gin.Context) {
 	})
 }
 
+// GetClusterDetail 返回集群完整信息（含 token/kube_config，供编辑回填） // Logan.Li
+func (h *K8sHandler) GetClusterDetail(c *gin.Context) {
+	id, _ := strconv.Atoi(c.Param("id"))
+
+	var cluster models.K8sCluster
+	if err := h.db.First(&cluster, id).Error; err != nil {
+		c.JSON(http.StatusNotFound, models.Response{
+			Code:    404,
+			Message: "集群不存在",
+		})
+		return
+	}
+
+	// 返回时手动脱敏：token/kube_config 只返回是否存在标记，不返回原文
+	c.JSON(http.StatusOK, models.Response{
+		Code:    200,
+		Message: "success",
+		Data: map[string]interface{}{
+			"id":            cluster.ID,
+			"name":          cluster.Name,
+			"code":          cluster.Code,
+			"version":       cluster.Version,
+			"status":        cluster.Status,
+			"config_type":   cluster.ConfigType,
+			"api_server":    cluster.APIServer,
+			"api_endpoint":  cluster.APIEndpoint,
+			"description":   cluster.Description,
+			"has_token":     cluster.Token != "",
+			"has_kube_config": cluster.KubeConfig != "",
+			"node_count":    cluster.NodeCount,
+			"pod_count":     cluster.PodCount,
+			"labels":        cluster.Labels,
+			"created_at":    cluster.CreatedAt,
+			"updated_at":    cluster.UpdatedAt,
+		},
+	})
+}
+
 // DeleteCluster 删除集群
 // @Summary 删除集群
 // @Description 删除指定K8s集群

backend/internal/api/routes/routes.go

@@ -236,6 +236,7 @@ func Register(r *gin.Engine, db *gorm.DB, log *zap.Logger, cfg *config.Config, c
 	{
 		clusters.GET("", k8sHandler.ListClusters)
 		clusters.GET("/:id", k8sHandler.GetCluster)
+		clusters.GET("/:id/detail", k8sHandler.GetClusterDetail) // 编辑用详情（含 has_token 标记） // Logan.Li
 		clusters.POST("", k8sHandler.CreateCluster)
 		clusters.PUT("/:id", k8sHandler.UpdateCluster)
 		clusters.DELETE("/:id", k8sHandler.DeleteCluster)