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/domain/service/workspace_service.go

@@ -0,0 +1,121 @@
+package service
+
+import (
+	"context"
+	"github.com/ocdp/cluster-service/internal/domain/entity"
+	"github.com/ocdp/cluster-service/internal/domain/repository"
+)
+
+// WorkspaceService 工作空间领域服务
+type WorkspaceService struct {
+	workspaceRepo repository.WorkspaceRepository
+	quotaRepo     repository.QuotaRepository
+	userRepo      repository.UserRepository
+}
+
+// NewWorkspaceService 创建工作空间服务
+func NewWorkspaceService(
+	workspaceRepo repository.WorkspaceRepository,
+	quotaRepo repository.QuotaRepository,
+	userRepo repository.UserRepository,
+) *WorkspaceService {
+	return &WorkspaceService{
+		workspaceRepo: workspaceRepo,
+		quotaRepo:     quotaRepo,
+		userRepo:      userRepo,
+	}
+}
+
+// Create 创建工作空间
+func (s *WorkspaceService) Create(ctx context.Context, name, description, createdBy string) (*entity.Workspace, error) {
+	// 检查名称是否已存在
+	existing, _ := s.workspaceRepo.GetByName(ctx, name)
+	if existing != nil {
+		return nil, entity.ErrWorkspaceExists
+	}
+
+	workspace := entity.NewWorkspace(name, description, createdBy)
+	if err := s.workspaceRepo.Create(ctx, workspace); err != nil {
+		return nil, err
+	}
+
+	return workspace, nil
+}
+
+// GetByID 获取工作空间
+func (s *WorkspaceService) GetByID(ctx context.Context, id string) (*entity.Workspace, error) {
+	return s.workspaceRepo.GetByID(ctx, id)
+}
+
+// GetByName 获取工作空间
+func (s *WorkspaceService) GetByName(ctx context.Context, name string) (*entity.Workspace, error) {
+	return s.workspaceRepo.GetByName(ctx, name)
+}
+
+// Update 更新工作空间
+func (s *WorkspaceService) Update(ctx context.Context, workspace *entity.Workspace) error {
+	return s.workspaceRepo.Update(ctx, workspace)
+}
+
+// Delete 删除工作空间
+func (s *WorkspaceService) Delete(ctx context.Context, id string) error {
+	// 删除关联的配额
+	if err := s.quotaRepo.DeleteByWorkspace(ctx, id); err != nil {
+		return err
+	}
+
+	return s.workspaceRepo.Delete(ctx, id)
+}
+
+// List 列出所有工作空间
+func (s *WorkspaceService) List(ctx context.Context) ([]*entity.Workspace, error) {
+	return s.workspaceRepo.List(ctx)
+}
+
+// GetQuotas 获取工作空间配额
+func (s *WorkspaceService) GetQuotas(ctx context.Context, workspaceID string) ([]*entity.WorkspaceQuota, error) {
+	return s.quotaRepo.GetByWorkspace(ctx, workspaceID)
+}
+
+// SetQuota 设置配额
+func (s *WorkspaceService) SetQuota(ctx context.Context, workspaceID string, resourceType entity.ResourceType, hardLimit, softLimit float64) (*entity.WorkspaceQuota, error) {
+	quota := entity.NewWorkspaceQuota(workspaceID, resourceType, hardLimit, softLimit)
+	if err := s.quotaRepo.Create(ctx, quota); err != nil {
+		return nil, err
+	}
+	return quota, nil
+}
+
+// SetQuotas 批量设置配额
+func (s *WorkspaceService) SetQuotas(ctx context.Context, workspaceID string, quotas map[entity.ResourceType]struct {
+	HardLimit float64
+	SoftLimit float64
+}) error {
+	for resourceType, config := range quotas {
+		quota := entity.NewWorkspaceQuota(workspaceID, resourceType, config.HardLimit, config.SoftLimit)
+		if err := s.quotaRepo.Create(ctx, quota); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// GetOrCreateDefaultQuota 获取或创建默认配额
+func (s *WorkspaceService) GetOrCreateDefaultQuota(ctx context.Context, workspaceID string, resourceType entity.ResourceType) (*entity.WorkspaceQuota, error) {
+	quota, _ := s.quotaRepo.GetByWorkspaceAndType(ctx, workspaceID, resourceType)
+	if quota != nil {
+		return quota, nil
+	}
+
+	// 创建默认配额（无限制）
+	quota = entity.NewWorkspaceQuota(workspaceID, resourceType, 0, 0)
+	if err := s.quotaRepo.Create(ctx, quota); err != nil {
+		return nil, err
+	}
+	return quota, nil
+}
+
+// GetUsers 获取工作空间的用户
+func (s *WorkspaceService) GetUsers(ctx context.Context, workspaceID string) ([]*entity.User, error) {
+	return s.userRepo.ListByWorkspace(ctx, workspaceID)
+}