feat(inbounds): add Real client IP presets to capture visitor IP behind CDN/relay

Surface the existing sockopt knobs (acceptProxyProtocol, trustedXForwardedFor) as a guided 'Real client IP' preset selector in the inbound form, so the real visitor IP is recovered behind Cloudflare CDN or an L4 tunnel/relay instead of recording the intermediary address. Presets are mutually exclusive, warn on incompatible transports, and add tooltips, docs, and translations for all locales.

frontend/src/pages/inbounds/form/InboundFormModal.tsx

@@ -818,7 +818,7 @@ export default function InboundFormModal({
         <ExternalProxyForm toggleExternalProxy={toggleExternalProxy} />
       )}
 
-      <SockoptForm toggleSockopt={toggleSockopt} />
+      <SockoptForm toggleSockopt={toggleSockopt} network={network as string} />
 
       {/* Transport masks don't apply to tunnel (a transparent forwarder), so
           its stream tab is just sockopt + TProxy. */}