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/single-post/cover.css

@@ -3,14 +3,14 @@
  * The cover stays inside the content column with a fixed aspect ratio box.
  * ============================================================ */
 
-/* ===== Cover (in-column ratio box) — Zibll .single-cover ===== */
+/* ===== Cover (in-column ratio box) — legacy .single-cover ===== */
 .single-cover {
     position: relative;
     overflow: hidden;
     border-radius: var(--main-radius, var(--radius, 8px));
     box-shadow: 0 0 10px var(--main-shadow, rgba(116, 116, 116, 0.08));
     margin-bottom: 20px;
-    /* Zibll: padding-bottom: calc(var(--single-cover-scale) + 50px) */
+    /* legacy: padding-bottom: calc(var(--single-cover-scale) + 50px) */
     padding-bottom: calc(var(--single-cover-scale, 35%) + 50px);
 }
 
@@ -46,7 +46,7 @@
     font-weight: 700;
 }
 
-/* Legacy overlay helpers (kept for non-zibll markup) */
+/* Legacy overlay helpers (kept for non-legacy markup) */
 .single-cover__overlay {
     position: absolute;
     inset: 0;
@@ -180,7 +180,7 @@
     position: relative;
 }
 
-/* line-form-line geometry owned by zibll-utilities.css (absolute full-width bottom).
+/* line-form-line geometry owned by legacy-utilities.css (absolute full-width bottom).
  * Here only ensure the meta row has height so the rule sits correctly. */
 .article-header .article-avatar .relative {
     margin-top: 20px;
@@ -210,7 +210,7 @@
 
 
 
-/* ===== Video footer (Zibll single-video-footer) ===== */
+/* ===== Video footer (legacy single-video-footer) ===== */
 .single-head-cover .single-video-footer { padding: 12px 4px 4px; }
 .single-head-cover .single-video-footer .article-title {
     font-size: clamp(1.1rem, 2.4vw, 1.45rem); font-weight: 700; margin: 8px 0 0; line-height: 1.35;
@@ -226,8 +226,8 @@
 .single-head-cover .cover-meta.single-metabox {
     display: flex; flex-wrap: wrap; gap: 8px 12px; font-size: 12px; color: var(--color-ink-4);
 }
-/* Pay box root — Zibll #posts-pay.zib-widget.pay-box */
-#posts-pay.zib-widget,
+/* Pay box root — legacy #posts-pay.aksrt-panel.pay-box */
+#posts-pay.aksrt-panel,
 #posts-pay.pay-box,
 .aksrt-single-pay-box {
   margin: 16px 0 20px;