Settings → MAILBOXES: удалить ящик вместе с письмами

DELETE /api/admin/mailboxes/{id} (только администратор, не свой ящик):
файлы вложений, затем строка users — папки, письма, исходники, контакты,
участие в рассылках и доступы уходят каскадом. Кнопка с подтверждением.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/app/core/api.service.ts

@@ -55,6 +55,9 @@ export class ApiService {
   setMailboxActive(id: number, active: boolean): Observable<Mailbox> {
     return this.http.put<Mailbox>(`/api/admin/mailboxes/${id}/active`, { active });
   }
+  deleteMailbox(id: number): Observable<void> {
+    return this.http.delete<void>(`/api/admin/mailboxes/${id}`);
+  }
 
   // folders
   folders(): Observable<Folder[]> { return this.http.get<Folder[]>('/api/folders'); }

frontend/src/app/pages/settings/mailboxes.section.ts

@@ -91,6 +91,9 @@ import { AuthService } from '../../core/auth.service';
               <button type="button" class="ghost-btn !py-1" (click)="toggle(m)"
                       [attr.aria-label]="(m.active ? 'Switch off ' : 'Switch on ') + m.email">
                 <mat-icon>{{ m.active ? 'toggle_on' : 'toggle_off' }}</mat-icon></button>
+              <button type="button" class="ghost-btn !py-1 hover:text-rose-400" (click)="remove(m)"
+                      [attr.aria-label]="'Delete ' + m.email" title="Delete the mailbox with all its mail">
+                <mat-icon>delete</mat-icon></button>
             }
             @if (membersOf() === m.id) {
               <div class="basis-full mt-1 p-2 rounded-lg border border-cyan-500/20">
@@ -227,6 +230,14 @@ export class MailboxesSection {
     });
   }
 
+  remove(m: Mailbox): void {
+    if (!confirm('Delete ' + m.email + ' with ALL its mail? This can not be undone.')) return;
+    this.api.deleteMailbox(m.id).subscribe({
+      next: () => { this.toasts.ok(m.email + ' deleted'); this.load(); },
+      error: e => this.toasts.error(errorText(e))
+    });
+  }
+
   copy(text: string): void {
     navigator.clipboard?.writeText(text).then(() => this.toasts.ok('Copied'), () => this.toasts.error('Copy it by hand'));
   }