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/css/frontend/layout.css

@@ -57,7 +57,7 @@
  * body.site-layout-2 = sidebar right
  * body.site-layout-3 = sidebar left
  *
- * This intentionally uses Zibll's float/negative-margin ownership model.
+ * This intentionally uses legacy's float/negative-margin ownership model.
  * Below 992px the sidebar is hidden and the content margins collapse.
  * ============================================================ */
 
@@ -68,7 +68,7 @@ main.content-shell,
 }
 
 /* content-shell is a padding shell for non-dual pages; when it also hosts
- * the float dual-column, kill horizontal padding so negative-margin math matches Zibll. */
+ * the float dual-column, kill horizontal padding so negative-margin math matches legacy. */
 main.container.content-shell,
 main.content-shell.container,
 .site-main.container.content-shell {
@@ -92,7 +92,7 @@ main.content-shell::after,
  * Critical: .content-layout must NOT set width:100%. Under box-sizing:border-box
  * a 100% width + margin-right gutter keeps the border-box at full container
  * width, so the gutter never shrinks the content box and .sidebar (margin-left:-311px)
- * sits under the main column (overlap). Zibll only sets margin on .content-layout;
+ * sits under the main column (overlap). legacy only sets margin on .content-layout;
  * width stays auto so margin carves out the column. */
 .content-wrap {
   float: left;
@@ -118,10 +118,10 @@ main.content-shell::after,
   max-width: 100%;
 }
 
-/* Base sidebar column (Zibll .sidebar defaults) — layout variants override below */
+/* Base sidebar column (legacy .sidebar defaults) — layout variants override below */
 .sidebar {
   float: left;
-  width: 311px; /* Zibll hard 311px; --sidebar-width kept in sync via runtime vars */
+  width: 311px; /* legacy hard 311px; --sidebar-width kept in sync via runtime vars */
   width: var(--sidebar-width, 311px);
   min-width: 0;
   position: relative;
@@ -152,7 +152,7 @@ body.site-layout-1 .content-layout--no-sidebar,
   margin-right: 0 !important;
 }
 
-/* Sidebar RIGHT (layout 2) — Zibll: margin-right: calc(311px + 15px) only */
+/* Sidebar RIGHT (layout 2) — legacy: margin-right: calc(311px + 15px) only */
 body.site-layout-2 .content-layout,
 .site-layout-2 .content-layout {
   margin-right: calc(311px + 15px);
@@ -207,7 +207,7 @@ body.site-layout-3 .sidebar,
   }
 }
 
-/* Mobile collapse (Zibll max-width: 991px) */
+/* Mobile collapse (legacy max-width: 991px) */
 @media (max-width: 991.98px) {
   body.site-layout-2 .content-layout,
   body.site-layout-3 .content-layout,
@@ -586,7 +586,7 @@ body.site-layout-3 .sidebar,
   pointer-events: none;
 }
 
-/* ========== 移动端/平板隐藏侧栏（与 zibll 一致：991px 以下隐藏） ========== */
+/* ========== 移动端/平板隐藏侧栏（与 legacy 一致：991px 以下隐藏） ========== */
 @media (max-width: 991px) {
   .content-layout__aside {
     display: none;