feat: add account menu and redirect after Q&A logout

Add the top-right account icon with the signed-in name and logout link. Expire the Q&A session before redirecting to the configured inquiry homepage in both environments. Preserve login return URL checks and ignore request-controlled logout destinations.

Validation: 106 tests, syntax checks, and mocked Chromium desktop/mobile regressions pass, including session-cookie removal and the destination navigation request with external networking blocked.

egbim/app.js

@@ -501,6 +501,18 @@
       console.error('[QA] SSO session load failed:', error);
       return getAuthUser();
     }).then(function (user) { renderAuth(user); return user; });
+    const accountMenu = qs('#accountMenu');
+    if (accountMenu) {
+      document.addEventListener('click', function (event) {
+        if (!accountMenu.contains(event.target)) accountMenu.open = false;
+      });
+      document.addEventListener('keydown', function (event) {
+        if (event.key === 'Escape' && accountMenu.open) {
+          accountMenu.open = false;
+          qs('#accountButton').focus();
+        }
+      });
+    }
     const menuButton = qs('.menu-button');
     const nav = qs('.global-nav');
     if (menuButton && nav) {