feat(tenants): add delete button to tenant list page

Each tenant row now has a Delete button with confirmation dialog.
Previously delete was only accessible from the detail page which
had no navigation link from the list.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

it0-web-admin/src/app/(admin)/tenants/page.tsx

@@ -73,6 +73,7 @@ export default function TenantsPage() {
   const [showCreate, setShowCreate] = useState(false);
   const [expandedId, setExpandedId] = useState<string | null>(null);
   const [editingId, setEditingId] = useState<string | null>(null);
+  const [deletingId, setDeletingId] = useState<string | null>(null);
   const [editPlan, setEditPlan] = useState<Tenant['plan']>('free');
   const [editQuota, setEditQuota] = useState<TenantQuota>({
     maxServers: 0,
@@ -115,6 +116,12 @@ export default function TenantsPage() {
     onSuccess: invalidate,
   });
 
+  const deleteMutation = useMutation({
+    mutationFn: (id: string) =>
+      apiClient(`/api/v1/admin/tenants/${id}`, { method: 'DELETE' }),
+    onSuccess: () => { invalidate(); setDeletingId(null); },
+  });
+
   /* ---- helpers ---- */
   function resetCreateForm() {
     setShowCreate(false);
@@ -335,6 +342,12 @@ export default function TenantsPage() {
                             >
                               {expandedId === tenant.id ? t('actions.hideQuotas') : t('actions.quotas')}
                             </button>
+                            <button
+                              onClick={() => setDeletingId(tenant.id)}
+                              className="px-2 py-1 text-xs rounded bg-red-100 text-red-700 hover:bg-red-200 dark:bg-red-900 dark:text-red-300"
+                            >
+                              {tc('delete')}
+                            </button>
                           </>
                         )}
                       </div>
@@ -367,6 +380,32 @@ export default function TenantsPage() {
           </table>
         </div>
       )}
+
+      {/* Delete confirmation dialog */}
+      {deletingId && (
+        <div className="fixed inset-0 bg-black/50 flex items-center justify-center z-50">
+          <div className="bg-card border rounded-lg p-6 max-w-sm w-full mx-4 space-y-4">
+            <h2 className="text-lg font-semibold">{t('deleteDialog.title')}</h2>
+            <p className="text-sm text-muted-foreground">{t('deleteDialog.message')}</p>
+            <div className="flex gap-3 justify-end">
+              <button
+                onClick={() => setDeletingId(null)}
+                disabled={deleteMutation.isPending}
+                className="px-4 py-2 text-sm border rounded-md hover:bg-muted"
+              >
+                {tc('cancel')}
+              </button>
+              <button
+                onClick={() => deleteMutation.mutate(deletingId)}
+                disabled={deleteMutation.isPending}
+                className="px-4 py-2 text-sm bg-destructive text-destructive-foreground rounded-md hover:opacity-90 disabled:opacity-50"
+              >
+                {deleteMutation.isPending ? tc('deleting') : tc('delete')}
+              </button>
+            </div>
+          </div>
+        </div>
+      )}
     </div>
   );
 }