feat: add Vitest unit testing infrastructure with initial test suite.

src/test/utils/test-utils.tsx

@@ -0,0 +1,22 @@
+import type { ReactElement } from 'react'
+import { render, type RenderOptions } from '@testing-library/react'
+
+// Custom render function that includes any providers your app needs
+// This can be extended later with Zustand store providers, etc.
+
+type CustomRenderOptions = Omit<RenderOptions, 'wrapper'>
+
+const customRender = (
+  ui: ReactElement,
+  options?: CustomRenderOptions
+) => {
+  // If you need to wrap components with providers (like Zustand store),
+  // you can create an AllTheProviders wrapper here
+  
+  return render(ui, options)
+}
+
+// Re-export everything from testing-library/react
+// eslint-disable-next-line react-refresh/only-export-components
+export * from '@testing-library/react'
+export { customRender as render }