chore: scaffold astro frontend with static output

frontend/vitest.config.ts

@@ -0,0 +1,9 @@
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    environment: 'happy-dom',
+    include: ['src/tests/**/*.test.ts', 'src/tests/**/*.test.tsx'],
+    globals: false,
+  },
+});