feat(wireguard): client config UX, collapsible config card, configurable DNS

Land the WireGuard client-config UX work on main (the upstream PR #5642
branch could not be pushed to).

- Reusable collapsible ConfigBlock (copy/download/QR, actions aligned right)
  for the client .conf, used by client info and the public sub page.
- Correct .conf: canonical PresharedKey casing and DNS sourced from the inbound
  (configurable per-inbound, default 1.1.1.1, 1.0.0.1).
- Configurable per-inbound DNS for WireGuard (schema + form + backend hint via
  InboundOption.WgDns); inert at the Xray layer.
- Public sub page now shows the WireGuard config, rebuilt from the share link;
  the Go wireguard:// link carries dns/presharedkey/keepalive for completeness.
- QR enabled for the wireguard:// link; link rows are compact like other protocols.
- Client information order is subscription, copy URL, WireGuard config; the
  redundant config tab is removed from the add/edit client modal.
- Drop the Inbound Information and QR Code row actions for WireGuard inbounds.

frontend/src/pages/sub/SubPage.tsx

@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useMemo, useState } from 'react';
+import { Fragment, useCallback, useEffect, useMemo, useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import {
   Button,
@@ -31,8 +31,9 @@ import {
 } from '@ant-design/icons';
 
 import { ClipboardManager, IntlUtil, LanguageManager } from '@/utils';
-import { isPostQuantumLink } from '@/lib/xray/inbound-link';
+import { isPostQuantumLink, wireguardConfigFromLink } from '@/lib/xray/inbound-link';
 import { LinkTags, parseLinkParts } from '@/lib/xray/link-label';
+import ConfigBlock from '@/components/clients/ConfigBlock';
 import { setMessageInstance } from '@/utils/messageBus';
 import { pauseAnimationsUntilLeave, useTheme } from '@/hooks/useTheme';
 import SubUsageSummary from './SubUsageSummary';
@@ -423,8 +424,10 @@ export default function SubPage() {
                         const rowTitle = parts?.remark || fallback;
                         const qrLabel = parts?.remark || rowTitle;
                         const canQr = !isPostQuantumLink(link);
+                        const isWireguardLink = link.startsWith('wireguard://') || link.startsWith('wg://');
                         return (
-                          <div key={link} className="sub-link-row">
+                          <Fragment key={link}>
+                          <div className="sub-link-row">
                             {parts
                               ? <LinkTags parts={parts} />
                               : <Tag className="sub-link-tag">LINK</Tag>}
@@ -468,6 +471,16 @@ export default function SubPage() {
                               )}
                             </div>
                           </div>
+                          {isWireguardLink && (
+                            <ConfigBlock
+                              label={t('pages.clients.wireguardConfig')}
+                              text={wireguardConfigFromLink(link, rowTitle)}
+                              fileName={`${rowTitle || 'peer'}.conf`}
+                              qrRemark={rowTitle}
+                              tagColor="cyan"
+                            />
+                          )}
+                          </Fragment>
                         );
                       })}
                     </div>