feat(frontend): add Helm chart browser, monitoring, chart-references and values templates pages

Add new frontend pages for the multi-tenant OCDP platform:

- Charts page (/charts): Browse Harbor OCI registries to list Helm chart repositories
  and versions, with deploy modal to launch charts on selected clusters
- Monitoring page (/monitoring): Display cluster metrics (CPU/Memory/GPU usage)
  and per-node details with resource utilization bars
- Chart References page (/chart-references): CRUD for chart metadata references
- Values Templates page (/templates): CRUD for Helm values templates with version
  history and rollback support
- Sidebar: Add Charts navigation, update Storage and Templates links
- api.ts: Add all API client functions (clusterApi, registryApi, instanceApi,
  monitoringApi, storageApi, chartReferenceApi, valuesTemplateApi,
  workspaceApi, userApi) with full TypeScript types

Note: deploy flow and values template rollback not yet end-to-end tested.

backend/internal/adapter/input/http/dto/cluster_dto.go

@@ -2,30 +2,36 @@ package dto
 
 // CreateClusterRequest 创建集群请求
 type CreateClusterRequest struct {
-	Name        string `json:"name" binding:"required"`
-	Host        string `json:"host" binding:"required"`
-	CAData      string `json:"caData"`
-	CADataAlt   string `json:"ca_data"`
-	CertData    string `json:"certData"`
-	CertDataAlt string `json:"cert_data"`
-	KeyData     string `json:"keyData"`
-	KeyDataAlt  string `json:"key_data"`
-	Token       string `json:"token"`
-	Description string `json:"description"`
+	Name             string `json:"name" binding:"required"`
+	Host             string `json:"host" binding:"required"`
+	CAData           string `json:"caData"`
+	CADataAlt        string `json:"ca_data"`
+	CertData         string `json:"certData"`
+	CertDataAlt      string `json:"cert_data"`
+	KeyData          string `json:"keyData"`
+	KeyDataAlt       string `json:"key_data"`
+	Token            string `json:"token"`
+	Description      string `json:"description"`
+	IsolationMode    string `json:"isolationMode"`    // 'namespace' | 'cluster'
+	DefaultNamespace string `json:"defaultNamespace"` // 默认 namespace 前缀
+	IsShared         bool   `json:"isShared"`         // 是否为共享集群
 }
 
 // UpdateClusterRequest 更新集群请求
 type UpdateClusterRequest struct {
-	Name        string `json:"name"`
-	Host        string `json:"host"`
-	CAData      string `json:"caData"`
-	CADataAlt   string `json:"ca_data"`
-	CertData    string `json:"certData"`
-	CertDataAlt string `json:"cert_data"`
-	KeyData     string `json:"keyData"`
-	KeyDataAlt  string `json:"key_data"`
-	Token       string `json:"token"`
-	Description string `json:"description"`
+	Name             string `json:"name"`
+	Host             string `json:"host"`
+	CAData           string `json:"caData"`
+	CADataAlt        string `json:"ca_data"`
+	CertData         string `json:"certData"`
+	CertDataAlt      string `json:"cert_data"`
+	KeyData          string `json:"keyData"`
+	KeyDataAlt       string `json:"key_data"`
+	Token            string `json:"token"`
+	Description      string `json:"description"`
+	IsolationMode    string `json:"isolationMode"`
+	DefaultNamespace string `json:"defaultNamespace"`
+	IsShared         *bool  `json:"isShared"`
 }
 
 // Normalize 将多种命名风格的字段合并到统一字段
@@ -56,10 +62,16 @@ func (r *UpdateClusterRequest) Normalize() {
 
 // ClusterResponse 集群响应（敏感数据已脱敏）
 type ClusterResponse struct {
-	ID          string `json:"id"`
-	Name        string `json:"name"`
-	Host        string `json:"host"`
-	Description string `json:"description"`
+	ID               string `json:"id"`
+	WorkspaceID      string `json:"workspaceId,omitempty"`
+	OwnerID          string `json:"ownerId,omitempty"`
+	Name             string `json:"name"`
+	Host             string `json:"host"`
+	Description      string `json:"description"`
+	IsolationMode    string `json:"isolationMode"`    // 'namespace' | 'cluster'
+	DefaultNamespace string `json:"defaultNamespace"` // 默认 namespace 前缀
+	IsShared         bool   `json:"isShared"`         // 是否为共享集群
+
 	// 认证配置状态（不返回实际证书数据，仅返回是否已配置）
 	HasCAData   bool `json:"hasCaData"`
 	HasCertData bool `json:"hasCertData"`