[Lang] fix persistance

site/scripts/main.js

@@ -46,6 +46,27 @@ window.addEventListener("DOMContentLoaded", () => {
 
   window.addEventListener("resize", () => isMenuOpen() && closeMenu());
   main.addEventListener("click", () => isMenuOpen() && closeMenu());
+
+  /* Language persistence */
+  const currentLang = document.documentElement.lang || "sr";
+  const anchors = document.getElementsByTagName("a");
+  Array.from(anchors).forEach((a) => {
+    // Skip language switcher links
+    if (a.classList.contains("lang")) return;
+    const href = a.getAttribute("href");
+    if (!href) return;
+    if (href.startsWith("/")) {
+      // Replace existing language prefix or add one
+      if (href.startsWith("/sr") || href.startsWith("/en")) {
+        if (!href.startsWith(`/${currentLang}`)) {
+          a.setAttribute("href", `/${currentLang}${href.slice(3)}`);
+        }
+      } else {
+        // No language prefix, prepend currentLang
+        a.setAttribute("href", `/${currentLang}${href}`);
+      }
+    }
+  });
   hamburger?.addEventListener("click", () => isMenuOpen() ? closeMenu() : openMenu());
 
   themeBtn.addEventListener("click", () => {