fix(frontend): serialize bulk client delete + drop deprecated Alert.message

useClients.removeMany was firing all DELETEs in parallel via Promise.all.
The 3x-ui backend mutates a single config JSON per request (read /
modify / write), so 20 concurrent deletes raced on the same file: every
request reported success, but only the last writer's copy stuck — about
half the selected clients reappeared after the toast. Replace the
parallel fan-out with a sequential for-of loop so each delete sees the
committed state of the previous one. The trade-off is total latency
(20 * ~250ms = ~5s) which is the correct behavior until the backend
grows a proper /bulkDel endpoint.

Also rename the Alert `message` prop to `title` in
ClientBulkAdjustModal to clear the AntD v6 deprecation warning.

frontend/src/hooks/useClients.ts

@@ -212,10 +212,12 @@ export function useClients() {
   const removeManyMut = useMutation({
     mutationFn: async ({ emails, keepTraffic }: { emails: string[]; keepTraffic?: boolean }) => {
       const suffix = keepTraffic ? '?keepTraffic=1' : '';
-      const results = await Promise.all(emails.map((email) => {
+      const results: Msg<unknown>[] = [];
+      for (const email of emails) {
         const url = `/panel/api/clients/del/${encodeURIComponent(email)}${suffix}`;
-        return HttpUtil.post(url, undefined, { silent: true });
-      }));
+        const res = await HttpUtil.post(url, undefined, { silent: true });
+        results.push(res);
+      }
       return results;
     },
     onSuccess: () => invalidateAll(),

frontend/src/pages/clients/ClientBulkAdjustModal.tsx

@@ -75,7 +75,7 @@ export default function ClientBulkAdjustModal({ open, count, onOpenChange, onSub
           type="info"
           showIcon
           style={{ marginBottom: 16 }}
-          message={t('pages.clients.bulkAdjustHint')}
+          title={t('pages.clients.bulkAdjustHint')}
         />
         <Form layout="vertical">
           <Form.Item label={t('pages.clients.addDays')}>