fix: lock directory during assignment changes

myteamwallet_frontend_modern/src/app/features/users/users.html

@@ -15,10 +15,11 @@
         type="search"
         name="directorySearch"
         [value]="searchDraft()"
+        [disabled]="assignmentBusyUserId() !== null"
         (input)="searchDraft.set($any($event.target).value)"
       />
     </mat-form-field>
-    <button mat-stroked-button type="submit" [disabled]="loading()">Suchen</button>
+    <button mat-stroked-button type="submit" [disabled]="loading() || assignmentBusyUserId() !== null">Suchen</button>
   </form>
 
   @if (mutationError()) {
@@ -138,11 +139,21 @@
     </div>
 
     <nav class="pagination" aria-label="Benutzerseiten">
-      <button mat-button type="button" [disabled]="directory()!.page <= 1 || loading()" (click)="previousPage()">
+      <button
+        mat-button
+        type="button"
+        [disabled]="directory()!.page <= 1 || loading() || assignmentBusyUserId() !== null"
+        (click)="previousPage()"
+      >
         <mat-icon>chevron_left</mat-icon>Zurück
       </button>
       <span>Seite {{ directory()!.page }} · {{ directory()!.total }} Benutzer</span>
-      <button mat-button type="button" [disabled]="!directory()!.hasNextPage || loading()" (click)="nextPage()">
+      <button
+        mat-button
+        type="button"
+        [disabled]="!directory()!.hasNextPage || loading() || assignmentBusyUserId() !== null"
+        (click)="nextPage()"
+      >
         Weiter<mat-icon>chevron_right</mat-icon>
       </button>
     </nav>