refactor(assets): vendor 资产迁入标准目录并全仓去除 zibll 标识

- assets/vendor 全量迁移: fontawesome5→assets/fontawesome5, css→assets/css,
  js→assets/js/runtime(避开 14 个同名自有文件), img 合并去重→assets/img,
  fonts→assets/fonts; 删除 assets/vendor
- libs 五个与 widgets/third-party 字节相同的库不重复入库, loader paths 改指向
- 运行时切换: _win.uri=assets 根, loader baseUrl=/js/runtime, enlighter 注入
  路径同步; PHP 7 个引用文件切换并改名 $zibll_*→$runtime_*
- 去品牌: Qinver 头注释/品牌 console.log/演示链接清除, 默认文案中性化
- 功能标识符改名: zib__→aksrt__, zib_ajax→aksrt_ajax, window.zib→
  window.aksrtLegacy, zibllblock/*→aksrtblock/*, .zib-widget→.aksrt-panel,
  .zib-slider→.aksrt-slider, zib_menu_options meta 键等
- 自有 CSS 改名: legacy-utilities/compat-vars/footer shell
- admin SPA 重建; 契约测试同步(路径/断言/文件更名)
- 例外保留: tests/visual 对照环境与 fixtures 前缀(外部 Zibll 产品引用)

验证: php -l 133 个改动文件通过; runtime 86 个 JS node --check 通过;
契约测试 68/70(2 个失败经 stash 对照确认为存量问题)

assets/js/page-template.js

@@ -56,11 +56,11 @@
     content.dataset.aksrtTocBound = '1';
 
     var maxDepth = parseInt(content.dataset.aksrtTocDepth || '3', 10) || 3;
-    // zibll section-navs: only fill when heading count > 2 (≥3).
+    // legacy section-navs: only fill when heading count > 2 (≥3).
     var MIN_HEADINGS = 3;
 
     function getHeadings() {
-      // zibll scans h1–h4 inside [data-nav]; depth setting still caps lower levels.
+      // legacy scans h1–h4 inside [data-nav]; depth setting still caps lower levels.
       return Array.prototype.slice.call(content.querySelectorAll('h1, h2, h3, h4')).filter(function (heading) {
         if (heading.closest('.no-nav') || heading.classList.contains('item-heading')) {
           return false;
@@ -240,13 +240,13 @@
   }
 
   function initContentExpand() {
-    // Zibll-style: inject .read-more inside .limit-height and expand on click.
+    // legacy-style: inject .read-more inside .limit-height and expand on click.
     document.querySelectorAll('.wp-posts-content.limit-height, .limit-height[data-nav]').forEach(function (content) {
       if (content.dataset.aksrtExpandBound === '1') return;
       content.dataset.aksrtExpandBound = '1';
 
       var customMax = parseInt(content.getAttribute('data-maxheight') || content.dataset.maxheight || '0', 10);
-      // data-maxheight may be maxheight-80 (Zibll) or absolute maxheight; prefer style max-height.
+      // data-maxheight may be maxheight-80 (legacy) or absolute maxheight; prefer style max-height.
       var styleMax = 0;
       if (content.style && content.style.maxHeight) {
         styleMax = parseInt(content.style.maxHeight, 10) || 0;