Migrate to vite and some more stuff

- server: add a `Track` class
- server: add a create_track_class function
- client: migrate from vue-cli to vite

src/router/index.js

@@ -46,7 +46,7 @@ const routes = [
 ];
 
 const router = createRouter({
-  history: createWebHistory(process.env.BASE_URL),
+  history: createWebHistory(import.meta.env.BASE_URL),
   routes,
 });