refactor: full-stack restructure with multi-tenancy, workspace management, and K8s diagnostics

- Add Workspace domain (entity, repository, service, handler, DTO)
- Add multi-tenant K8s client with tenant binding and quota management
- Add K8s diagnostics client (instance diagnostics)
- Add authorization middleware (authz package)
- Restructure frontend to feature-based architecture (features/)
- Add User Management page in configuration
- Add AccessDenied page and route guards
- Refactor shared components (form inputs, layout, UI)
- Update Tailwind config for new design system
- Add comprehensive documentation (docs/, tasks/, plans)
- Improve cluster service with better kubeconfig handling
- Add tests for crypto, config, helm client, tenant binding

backend/internal/domain/repository/instance_repository.go

@@ -9,23 +9,22 @@ import (
 type InstanceRepository interface {
 	// Create 创建实例
 	Create(ctx context.Context, instance *entity.Instance) error
-	
+
 	// GetByID 根据 ID 获取实例
 	GetByID(ctx context.Context, id string) (*entity.Instance, error)
-	
+
 	// GetByClusterAndName 根据集群 ID 和名称获取实例
 	GetByClusterAndName(ctx context.Context, clusterID, name string) (*entity.Instance, error)
-	
+
 	// Update 更新实例
 	Update(ctx context.Context, instance *entity.Instance) error
-	
+
 	// Delete 删除实例
 	Delete(ctx context.Context, id string) error
-	
+
 	// ListByCluster 列出指定集群的所有实例
 	ListByCluster(ctx context.Context, clusterID string) ([]*entity.Instance, error)
-	
+
 	// List 列出所有实例
 	List(ctx context.Context) ([]*entity.Instance, error)
 }
-