scaffold: Vue 3 frontend — router, stores, views, composables, layouts

Complete frontend skeleton: Vite + Vue 3 + TypeScript + Tailwind CSS,
Pinia stores (auth, server, wipe, plugins), authenticated API composable,
full route tree with auth guards, DashboardLayout with sidebar nav,
23 view stubs across auth/admin/public, all TypeScript interfaces.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/App.vue

@@ -0,0 +1,7 @@
+<script setup lang="ts">
+import { RouterView } from 'vue-router'
+</script>
+
+<template>
+  <RouterView />
+</template>