Implement basic tests for webui

webui/src/test/setup.ts

@@ -0,0 +1,10 @@
+import '@testing-library/jest-dom'
+import { afterEach, vi } from 'vitest'
+
+// Mock fetch globally since your app uses fetch
+global.fetch = vi.fn()
+
+// Clean up after each test
+afterEach(() => {
+  vi.clearAllMocks()
+})