Add a revert to ngax theme button

src/app/layout/layout.component.html

@@ -37,6 +37,13 @@
     <div class="spacer"></div>
 
     <spk-list class="base-level-20 primary">
+      <button action (click)="changeDefaultClientTo('ngax')" i18n>
+        <spk-icon>skip-back</spk-icon>
+        Revert to NGAX client
+      </button>
+
+      <spk-divider />
+
       <button action routerLink="/about" routerLinkActive="active" i18n>
         <spk-icon>info</spk-icon>
         About duplicati

src/app/layout/layout.component.ts

@@ -2,6 +2,7 @@ import { ChangeDetectionStrategy, Component, inject } from '@angular/core';
 import { RouterLink, RouterLinkActive, RouterOutlet } from '@angular/router';
 import {
   SparkleButtonComponent,
+  SparkleDividerComponent,
   SparkleIconComponent,
   SparkleListComponent,
   SparkleSidenavComponent,
@@ -21,6 +22,7 @@ import { LayoutState } from './layout.state';
     SparkleIconComponent,
     SparkleListComponent,
     SparkleButtonComponent,
+    SparkleDividerComponent,
     ServiceHubComponent,
     LogoComponent,
   ],
@@ -41,4 +43,16 @@ export default class LayoutComponent {
   toggleBodyClass() {
     this.#layoutState.toggleBodyClass();
   }
+
+  changeDefaultClientTo(client: 'ngclient' | 'ngax') {
+    this.#setClientDefault(client);
+    window.location.replace(`/${client}`);
+  }
+
+  #setClientDefault(client: 'ngclient' | 'ngax') {
+    var d = new Date();
+    d.setTime(d.getTime() + 90 * 24 * 60 * 60 * 1000);
+
+    document.cookie = 'default-theme=' + client + '; expires=' + d.toUTCString() + '; path=/';
+  }
 }