Fixed visibility of top bar's impersonation.

src/app/navigation/topbar/topbar.component.html

@@ -5,7 +5,7 @@
   </button>
 
   <span>Tom-to-Speech</span>
-  @if (isTTSLoggedIn) {
+  @if (isLoggedIn) {
   <span class="spacer"></span>
   <div class="links">
     @if (showImpersonation) {
@@ -19,10 +19,12 @@
       }
     </div>
     }
+    @if (isAdminLoggedIn) {
     <button mat-icon-button
             (click)="showImpersonation = !showImpersonation">
       <mat-icon>supervisor_account</mat-icon>
     </button>
+    }
   </div>
   }
 </mat-toolbar>

src/app/navigation/topbar/topbar.component.ts

@@ -44,8 +44,12 @@ export class Topbar implements OnDestroy {
     }
   }
 
-  get isTTSLoggedIn() {
-    return this.client.logged_in;
+  get isLoggedIn() {
+    return this.auth.isAuthenticated();
+  }
+
+  get isAdminLoggedIn() {
+    return this.auth.isAuthenticated() && this.auth.isAdmin();
   }
 
   get username() {