phase 16: vitest + MSW frontend tests, CI integration

frontend/src/test/render.tsx

@@ -0,0 +1,42 @@
+import { type ReactNode } from 'react';
+import { render, type RenderOptions } from '@testing-library/react';
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
+import { RouterProvider, createMemoryHistory } from '@tanstack/react-router';
+import { router } from '../routes';
+
+function createTestQueryClient() {
+  return new QueryClient({
+    defaultOptions: {
+      queries: { retry: false, gcTime: 0 },
+      mutations: { retry: false },
+    },
+  });
+}
+
+export function renderWithProviders(
+  ui: ReactNode,
+  options?: RenderOptions,
+) {
+  const queryClient = createTestQueryClient();
+  function Wrapper({ children }: { children: ReactNode }) {
+    return (
+      <QueryClientProvider client={queryClient}>
+        {children}
+      </QueryClientProvider>
+    );
+  }
+  return render(ui, { wrapper: Wrapper, ...options });
+}
+
+export function renderRoute(path: string) {
+  const queryClient = createTestQueryClient();
+  const history = createMemoryHistory({ initialEntries: [path] });
+  const testRouter = Object.assign(router, {});
+  testRouter.update({ history });
+
+  return render(
+    <QueryClientProvider client={queryClient}>
+      <RouterProvider router={testRouter} />
+    </QueryClientProvider>,
+  );
+}