docs: site WIP, extractor type cleanup, tests preset; add broadcastedRef

Type the docs extractor's package.json parsing as unknown; comment the Vite
plugin version-skew cast; wire the tests preset; site/architecture WIP.

docs/app.vue

@@ -0,0 +1,13 @@
+<script setup lang="ts">
+const { data: home } = await useAsyncData(() => queryCollection('renovate').first());
+
+useSeoMeta({
+  title: home.value?.title,
+  description: home.value?.description,
+});
+</script>
+
+<template>
+  <ContentRenderer v-if="home" :value="home" />
+  <div v-else>Home not found</div>
+</template>