feat(hub): add dark/light theme toggle with moon and sun icons

Co-authored-by: Cursor <cursoragent@cursor.com>

manual_trading_hub/static/app.js

@@ -2645,6 +2645,9 @@
   initInstanceFrame();
   initFullscreen();
   initMobileLayout();
+  if (globalThis.HubTheme && typeof HubTheme.initToggleUI === "function") {
+    HubTheme.initToggleUI();
+  }
 
   function initShellNav() {
     document.querySelectorAll(".top-nav a[href^='/']").forEach((a) => {