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/enhancements.js

@@ -521,83 +521,11 @@
   }
 
   /* ============================================================
-   * 4. 导航溢出自动折叠
-   * 菜单项超出容器宽度时折叠进「更多」下拉
+   * 4. 导航溢出折叠
+   * 由 assets/js/core/nav.js（zibll 1:1 navFolding）负责。
+   * 此处不再重复实现，避免两套逻辑争抢 .aksrt-nav-more 节点
+   * 触发 NotFoundError: insertBefore (moreLi 已被对方 remove)。
    * ============================================================ */
-  function initNavOverflow() {
-    var nav = document.querySelector('.navbar-top .nav.navbar-nav');
-    if (!nav) return;
-
-    // 创建「更多」按钮
-    var moreLi = document.createElement('li');
-    moreLi.className = 'nav-item aksrt-nav-more';
-    moreLi.style.display = 'none';
-    moreLi.innerHTML =
-      '<button type="button" class="aksrt-nav-more__btn" aria-haspopup="true" aria-expanded="false">更多 <i class="fas fa-caret-down"></i></button>' +
-      '<ul class="aksrt-nav-more__dropdown"></ul>';
-    nav.appendChild(moreLi);
-
-    var moreBtn = moreLi.querySelector('.aksrt-nav-more__btn');
-    var dropdown = moreLi.querySelector('.aksrt-nav-more__dropdown');
-
-    moreBtn.addEventListener('click', function (e) {
-      e.stopPropagation();
-      var open = dropdown.classList.toggle('is-open');
-      moreBtn.setAttribute('aria-expanded', open ? 'true' : 'false');
-    });
-
-    document.addEventListener('click', function () {
-      dropdown.classList.remove('is-open');
-      moreBtn.setAttribute('aria-expanded', 'false');
-    });
-
-    function checkOverflow() {
-      var items = Array.from(nav.children).filter(function (el) {
-        return !el.classList.contains('aksrt-nav-more');
-      });
-
-      // 重置：把所有项移回原位
-      while (dropdown.firstChild) {
-        var li = dropdown.firstChild;
-        nav.insertBefore(li, moreLi);
-      }
-      moreLi.style.display = 'none';
-
-      var navWidth = nav.clientWidth;
-      var moreWidth = 80; // 预留「更多」按钮宽度
-      var usedWidth = 0;
-      var overflowItems = [];
-
-      items.forEach(function (item) {
-        usedWidth += item.offsetWidth;
-        if (usedWidth + moreWidth > navWidth) {
-          overflowItems.push(item);
-        }
-      });
-
-      if (overflowItems.length > 0) {
-        moreLi.style.display = '';
-        overflowItems.forEach(function (item) {
-          dropdown.appendChild(item);
-        });
-      }
-    }
-
-    // ResizeObserver 监听（避免 resize 抖动）
-    if ('ResizeObserver' in window) {
-      var timer = null;
-      var ro = new ResizeObserver(function () {
-        if (timer) clearTimeout(timer);
-        timer = setTimeout(checkOverflow, 100);
-      });
-      ro.observe(nav);
-    } else {
-      window.addEventListener('resize', checkOverflow, { passive: true });
-    }
-
-    // 初始检测
-    checkOverflow();
-  }
 
   /* ============================================================
    * 初始化入口
@@ -605,7 +533,6 @@
   document.addEventListener('DOMContentLoaded', function () {
     initLightbox();
     initScrollDirection();
-    initNavOverflow();
   });
 
 })();