add: Mobile menu button in top-left corner

js/app.js

@@ -32,11 +32,23 @@ window.updateIndicatorCandles = drawIndicatorsOnChart;
 window.IndicatorRegistry = IndicatorRegistry;
 
 document.addEventListener('DOMContentLoaded', async () => {
-    // Attach toggle sidebar event listener
+    // Attach toggle sidebar event listeners
     const toggleBtn = document.getElementById('sidebarToggleBtn');
     if (toggleBtn) {
         toggleBtn.addEventListener('click', toggleSidebar);
     }
+    
+    // Mobile menu button
+    const mobileMenuBtn = document.getElementById('mobileMenuBtn');
+    if (mobileMenuBtn) {
+        mobileMenuBtn.addEventListener('click', (e) => {
+            e.stopPropagation();
+            const sidebar = document.getElementById('rightSidebar');
+            if (sidebar) {
+                sidebar.classList.toggle('collapsed');
+            }
+        });
+    }
 
     // Initialize timezone selector
     const timezoneSelect = document.getElementById('timezoneSelect');