chore: add @tailwindcss/postcss and PostCSS setup for Tailwind v4

server/api/fixtures.post.ts

@@ -0,0 +1,11 @@
+import { defineEventHandler, readBody } from 'h3'
+import { useFixtureIO, type AppSnapshot } from '~/composables/useFixtureIO'
+
+export default defineEventHandler(async (event) => {
+  const body = (await readBody(event)) as AppSnapshot
+  const { importAll } = useFixtureIO()
+  importAll(body)
+  return { ok: true }
+})
+
+