feat(debt-dialog): add debt warning dialog for negative balance

frontend/src/app/shared/components/navbar/navbar.component.html

@@ -17,8 +17,9 @@
         @if (isLoggedIn) {
           <div
             class="text-white font-bold bg-deep-blue-contrast rounded-full px-4 py-2 text-sm hover:bg-deep-blue-contrast/80 hover:cursor-pointer hover:scale-105 transition-all active:scale-95 select-none duration-300"
+            routerLink="/home"
           >
-            <span>{{ balance() | currency: 'EUR' : 'symbol' : '1.2-2' }}</span>
+            <span [class]="balance() < 0 ? 'text-accent-red' : ''">{{ balance() | currency: 'EUR' : 'symbol' : '1.2-2' }}</span>
           </div>
           <button (click)="logout()" class="button-primary px-4 py-1.5">Abmelden</button>
         }