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/tsconfig.json

@@ -40,12 +40,6 @@
       "@validators": [
         "./src/@core/utils/validators"
       ],
-      "@db/*": [
-        "./src/plugins/fake-api/handlers/*"
-      ],
-      "@api-utils/*": [
-        "./src/plugins/fake-api/utils/*"
-      ]
     },
     "lib": [
       "esnext",