Implement basic tests for webui

webui/vite.config.ts

@@ -1,4 +1,4 @@
-import { defineConfig } from 'vite'
+import { defineConfig } from 'vitest/config'
 import react from '@vitejs/plugin-react'
 import path from "path"
 import tailwindcss from "@tailwindcss/vite"
@@ -14,5 +14,11 @@ export default defineConfig({
     proxy: {
       '/api': 'http://localhost:8080'
     }
-  }
+  },
+  test: {
+    globals: true,
+    environment: 'jsdom',
+    setupFiles: ['./src/test/setup.ts'],
+    css: true,
+  },
 })