Remove SSR support and associated server-side code.

This change eliminates Angular server-side rendering (SSR) features, including related files, dependencies, and configurations, simplifying the codebase. The update also adjusts routing and references to support client-side rendering exclusively.

frontend/src/app/app.routes.ts

@@ -1,4 +1,3 @@
 import { Routes } from '@angular/router';
-import {AppComponent} from './app.component';
 
-export const routes: Routes = [new AppComponent];
+export const routes: Routes = [];