fix: scale replicas in response, K8s metrics client, quota precheck, auth tests

- Add GetMetrics method to MetricsClient interface and implement cluster metrics API
- Add QuotaPrecheck service for validating resource quotas before deployment
- Add auth DTO with role/permission models and auth handler tests
- Add instance diagnostics: mounted NFS volumes, labels, annotations in pod diagnostics
- Update workspace handler with GetWorkspace endpoint and shared-user list
- Fix monitoring handler to use correct service method name
- Add tail_lines fallback in instance handler for snake_case query params
- Update nginx config for SSE log streaming support (no buffering)
- Add comprehensive test coverage: auth_service_test, auth_handler_test,
  auth_dto_test, metrics_client_test, quota_precheck_test
- Update error messages for quota validation and instance operations
- ModifyModal: fix YAML lineWidth:0, modified keys summary, delta-only submit
- InstanceCard: correctly disable scale-minus when replicas <= 0
- SidebarLayout: add hover transition for sidebar items
- Update todo.md and lessons.md with latest fixes

frontend/src/shared/components/layout/SidebarLayout/SidebarLayout.tsx

@@ -21,7 +21,7 @@ export default function SidebarLayout({ items, children }: SidebarLayoutProps) {
         isOpen={isSidebarOpen}
         onClose={() => setIsSidebarOpen(false)}
       />
-      <div className="relative z-10 flex flex-col flex-1">
+      <div className="relative z-10 flex min-w-0 flex-1 flex-col">
         {React.Children.map(children, (child) => {
           // 将 toggleSidebar 函数传递给子组件
           if (React.isValidElement(child)) {