fix(nav): stop dual overflow folders fighting on insertBefore

Remove legacy initNavOverflow from enhancements.js (core/nav.js owns
zibll navFolding). Harden clearFolding against detached more nodes and
skip counting existing .aksrt-nav-more during fold measurement.

assets/js/core/nav.js

@@ -18,16 +18,42 @@
   }
 
   function clearFolding() {
-    var more = document.querySelector(".navbar-nav > li.aksrt-nav-more");
-    if (!more) return;
-    var sub = more.querySelector(".sub-menu");
-    var nav = more.parentNode;
-    if (sub && nav) {
-      while (sub.firstChild) {
-        nav.insertBefore(sub.firstChild, more);
+    // Support both zibll-style more and any legacy .aksrt-nav-more nodes.
+    var mores = document.querySelectorAll(".navbar-nav > li.aksrt-nav-more");
+    Array.prototype.forEach.call(mores, function (more) {
+      var nav = more.parentNode;
+      if (!nav) {
+        more.remove();
+        return;
       }
-    }
-    more.remove();
+      // Prefer direct child .sub-menu (zibll contract); fall back to first matching submenu.
+      var sub = null;
+      for (var i = 0; i < more.children.length; i++) {
+        var child = more.children[i];
+        if (
+          child.tagName === "UL" &&
+          (child.classList.contains("sub-menu") ||
+            child.classList.contains("aksrt-nav-more__dropdown"))
+        ) {
+          sub = child;
+          break;
+        }
+      }
+      if (!sub) {
+        sub = more.querySelector(".sub-menu, .aksrt-nav-more__dropdown");
+      }
+      if (sub) {
+        while (sub.firstChild) {
+          // Guard: only insertBefore when more is still a child of nav.
+          if (more.parentNode === nav) {
+            nav.insertBefore(sub.firstChild, more);
+          } else {
+            nav.appendChild(sub.firstChild);
+          }
+        }
+      }
+      more.remove();
+    });
   }
 
   function navFolding() {
@@ -53,6 +79,7 @@
     var navsWidth = 66;
     var foldItems = [];
     Array.prototype.forEach.call(nav.children, function (li) {
+      if (li.classList.contains("aksrt-nav-more")) return;
       navsWidth += li.offsetWidth || 0;
       if (navsWidth > surplus) foldItems.push(li);
     });
@@ -63,7 +90,9 @@
     more.innerHTML =
       '<a href="javascript:void(0);"><i class="fas fa-bars" aria-hidden="true"></i></a><ul class="sub-menu"></ul>';
     var sub = more.querySelector(".sub-menu");
-    foldItems.forEach(function (li) { sub.appendChild(li); });
+    foldItems.forEach(function (li) {
+      if (li && li.parentNode) sub.appendChild(li);
+    });
     nav.appendChild(more);
     appendChevrons(more);
   }