feat: skip connect and terminal mount for remote sessions in openSession

When opts.sourceUrl is non-empty (remote session), skip the POST
/api/sessions/{name}/connect call and skip window._openTerminal(name).
Remote terminal connections are deferred to Phase 3.
Local sessions (empty sourceUrl) continue to work as before.

Co-authored-by: Amplifier <amplifier@amplified.dev>

muxplex/frontend/app.js

@@ -1086,10 +1086,13 @@ async function openSession(name, opts = {}) {
   if (fab) fab.classList.add('hidden');
 
   // Connect to session (kill old ttyd, spawn new one for this session)
+  var sourceUrl = opts.sourceUrl || '';
   try {
     if (!opts.skipConnect) {
+      if (!sourceUrl) {
         await api('POST', `/api/sessions/${name}/connect`);
       }
+    }
   } catch (err) {
     showToast(err.message || 'Connection failed');
     return closeSession();
@@ -1099,7 +1102,7 @@ async function openSession(name, opts = {}) {
   await animDone;
 
   // Mount terminal NOW — /connect has completed, new ttyd is serving the correct session
-  if (window._openTerminal) window._openTerminal(name);
+  if (!sourceUrl && window._openTerminal) window._openTerminal(name);
 }
 
 /**