rebuild(stage-1): establish isolated application skeleton

next/frontend/src/main.ts

@@ -0,0 +1,9 @@
+import { createPinia } from "pinia";
+import { createApp } from "vue";
+
+import App from "./app/App.vue";
+import router from "./app/router";
+import "./shared/styles/tokens.css";
+import "./shared/styles/base.css";
+
+createApp(App).use(createPinia()).use(router).mount("#app");