feat(portal): strip Vuexy demo content and create clean portal shell

Remove all demo pages, dialogs, sidebar navigation, and layout components.
Create minimal top-bar portal layout with auth-aware navigation, placeholder
pages for volunteer registration, dashboard, shifts, profile, artist advance,
and login. Add Pinia auth store, axios with Sanctum support, and router guards.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/portal/src/plugins/1.router/guards.ts

@@ -0,0 +1,28 @@
+import type { Router } from 'vue-router'
+import { useAuthStore } from '@/stores/useAuthStore'
+
+export function setupGuards(router: Router) {
+  router.beforeEach(async (to) => {
+    const authStore = useAuthStore()
+
+    if (!authStore.isInitialized) {
+      await authStore.initialize()
+    }
+
+    const requiresAuth = to.meta.requiresAuth === true
+
+    // Public routes — no auth check needed
+    if (!requiresAuth) {
+      // Redirect authenticated users away from login
+      if (authStore.isAuthenticated && to.path === '/login') {
+        return { path: '/dashboard' }
+      }
+      return
+    }
+
+    // Auth required — redirect to login if not authenticated
+    if (!authStore.isAuthenticated) {
+      return { path: '/login', query: { to: to.fullPath } }
+    }
+  })
+}