feat(frontend): add Vue 3 web application

- Add Vue 3 + TypeScript + Pinia setup
- Add 6 complete views: Dashboard, Queue, Scanner, Rules, Workers, Settings
- Add Pinia stores for state management
- Add API service with Axios client
- Add dark theme with Tdarr-inspired styling
- Add setup wizard component
- Add path browser for filesystem navigation

frontend/src/main.ts

@@ -0,0 +1,13 @@
+import { createApp } from 'vue'
+import { createPinia } from 'pinia'
+import App from './App.vue'
+import router from './router'
+import './assets/css/main.css'
+
+const app = createApp(App)
+
+app.use(createPinia())
+app.use(router)
+
+app.mount('#app')
+