feat(frontend): Vue 3 + wa-sqlite + sync engine + auth + layouts

- package.json with Vue 3, Pinia, vue-router, wa-sqlite, Tailwind CSS 4, Vite
- wa-sqlite database layer with IDBBatchAtomicVFS (offline-first)
- Full schema mirroring backend tables (vehicles, orders, invoices, etc.)
- SyncEngine: fullSync, incrementalSync, pushQueue for offline queue
- Auth store with JWT parsing, login/register, plan tier detection
- Router with all routes and auth navigation guards
- AppLayout (sidebar desktop / bottom nav mobile) + AuthLayout
- Login/Register views connected to API contract
- SyncIndicator component (online/offline status)
- Reactive SQL query composable (useSqlQuery)
- Placeholder views for dashboard, orders, vehicles, appointments, catalog, settings

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

frontend/package.json

@@ -0,0 +1,23 @@
+{
+  "name": "roaauto-frontend",
+  "version": "0.1.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "vue": "^3.5",
+    "vue-router": "^4.4",
+    "pinia": "^2.2",
+    "@journeyapps/wa-sqlite": "^1.0"
+  },
+  "devDependencies": {
+    "@vitejs/plugin-vue": "^5.2",
+    "vite": "^6.0",
+    "tailwindcss": "^4.0",
+    "@tailwindcss/vite": "^4.0",
+    "vite-plugin-pwa": "^0.21"
+  }
+}