fix: align terminal.js token response field with API contract and remove stale ttyd refs

- terminal.js:55: read data.port instead of data.muxtermPort to match
  the /api/terminal-token response shape ({token, port})
- test_terminal.mjs:37: update mock to return {port: 9999} matching API
- app.js: replace two stale ttyd references in comments with muxterm

muxplex/frontend/app.js

@@ -311,7 +311,7 @@ function trackInteraction() {
 /**
  * Restore application state from the server on page load.
  * Calls GET /api/state and, if an active session exists, re-opens it,
- * skipping only the zoom animation (ttyd is re-spawned to handle service restarts).
+ * skipping only the zoom animation (muxterm handles terminal sessions).
  * Always resolves — errors are logged as warnings so the app can start normally.
  * @returns {Promise<void>}
  */
@@ -2941,7 +2941,7 @@ async function openSession(name, opts = {}) {
   // Wait for animation to finish (may already be done if /connect was slow)
   await animDone;
 
-  // Mount terminal NOW — /connect has completed, new ttyd is serving the correct session
+  // Mount terminal NOW — muxterm is serving the correct session
   // Prefer _switchTerminal (cache-aware) over _openTerminal (always creates fresh)
   if (window._switchTerminal) window._switchTerminal(name, _deviceId, getDisplaySettings().fontSize);
   else if (window._openTerminal) window._openTerminal(name, _deviceId, getDisplaySettings().fontSize);

muxplex/frontend/terminal.js

@@ -52,7 +52,7 @@ function connectWebSocket() {
   fetch('/api/terminal-token', { method: 'GET' })
     .then(function(res) { return res.json(); })
     .then(function(data) {
-      _muxtermPort = data.muxtermPort;
+      _muxtermPort = data.port;
       _muxtermToken = data.token;
       _openMuxtermSocket();
     })

muxplex/frontend/tests/test_terminal.mjs

@@ -34,7 +34,7 @@ function loadTerminal() {
   let capturedCloseHandler = null;
   let lastFetchUrl = null;
   let lastFetchOpts = null;
-  let fetchReturnValue = { muxtermPort: 9999, token: 'test-token-abc' };
+  let fetchReturnValue = { port: 9999, token: 'test-token-abc' };
 
   const mockTerm = {
     cols: 80,