fix(gateway): close server in canBindToHost error handler

Ensure testServer.close() is called in both success and error paths
to prevent file descriptor leaks when bind fails.

CHANGELOG.md

@@ -36,6 +36,7 @@ Status: unreleased.
 
 ### Fixes
 - Web UI: improve WebChat image paste previews and allow image-only sends. (#1925) Thanks @smartprogrammer93.
+- Gateway: fix server resource leak in canBindToHost error handler.
 
 ## 2026.1.24-3
 

src/gateway/net.ts

@@ -140,6 +140,7 @@ export async function canBindToHost(host: string): Promise<boolean> {
   return new Promise((resolve) => {
     const testServer = net.createServer();
     testServer.once("error", () => {
+      testServer.close();
       resolve(false);
     });
     testServer.once("listening", () => {