refactor: clean up fetchJson try-catch destructuring in buildRequest call

Agent-Logs-Url: https://github.com/github/gh-aw-firewall/sessions/4eb4ca56-5f43-4a41-aa10-b29649ab9c9e

Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Author: Copilot

containers/api-proxy/model-discovery.js

@@ -66,9 +66,8 @@ function buildRequest(url, opts, timeoutMs) {
  */
 function fetchJson(url, opts, timeoutMs) {
   return new Promise((resolve) => {
-    let built;
-    try { built = buildRequest(url, opts, timeoutMs); } catch { resolve(null); return; }
-    const { mod, reqOpts } = built;
+    let mod, reqOpts;
+    try { ({ mod, reqOpts } = buildRequest(url, opts, timeoutMs)); } catch { resolve(null); return; }
 
     let settled = false;
     const resolveOnce = (value) => { if (settled) return; settled = true; resolve(value); };