feat(xray): add loopback sniffing and per-segment fragment masks

- Loopback outbound: add sniffing support (xray-core #6320)

- FinalMask fragment: support per-segment lengths/delays arrays with legacy length/delay migration (xray-core #6334)

- Consolidate sniffing into a shared SniffingFields component and the canonical SniffingSchema across inbound, VLESS reverse, and loopback

frontend/src/pages/xray/outbounds/protocols/loopback.tsx

@@ -1,11 +1,23 @@
 import { useTranslation } from 'react-i18next';
 import { Form, Input } from 'antd';
 
+import SniffingFields from '@/lib/xray/forms/SniffingFields';
+
 export default function LoopbackFields() {
   const { t } = useTranslation();
+  const form = Form.useFormInstance();
+
   return (
-    <Form.Item label={t('pages.xray.outboundForm.inboundTag')} name={['settings', 'inboundTag']}>
-      <Input placeholder={t('pages.xray.outboundForm.inboundTagPlaceholder')} />
-    </Form.Item>
+    <>
+      <Form.Item label={t('pages.xray.outboundForm.inboundTag')} name={['settings', 'inboundTag']}>
+        <Input placeholder={t('pages.xray.outboundForm.inboundTagPlaceholder')} />
+      </Form.Item>
+
+      <SniffingFields
+        name={['settings', 'sniffing']}
+        form={form}
+        enableLabel={t('pages.inbounds.sniffingTab')}
+      />
+    </>
   );
 }