more refactor in frontend javascript

web/js/theme.js

@@ -0,0 +1,10 @@
+let currentTheme = localStorage.getItem("theme") || "light";
+
+// Initialize theme
+document.body.setAttribute("data-theme", currentTheme);
+
+function toggleTheme() {
+  currentTheme = currentTheme === "light" ? "dark" : "light";
+  document.body.setAttribute("data-theme", currentTheme);
+  localStorage.setItem("theme", currentTheme);
+}