feat(runtime): 全站前端脚本统一接入 AksrtFrontend 全局 DOM 生命周期

- rehydrate.js 新增 boot()/aksrt:ready 事件，支持 boot 后晚注册立即以 init 触发
- aksrt-runtime.js 初始加载改走 AksrtFrontend.boot，tooltip/倒计时注册为组件
- 约 30 个前端脚本（首页、评论、支付、路由、页面叶子、widgets）
  从直接 DOMContentLoaded 迁移为 AksrtFrontend.register，并加幂等标记
- section-navs 依赖改为 aksrt-runtime，保证注册时序
- 清理死代码：删除孤儿 loader.js/main.js 及 runtime/page-navs 遗留副本
- loader.js 移除已迁移模块的 tbquire 路径映射，main.js 相应瘦身
- build-public-assets.mjs 增加 runtime/main.min.js 自动压缩步骤
- 新增 4 个契约测试（homepage-dom/rehydrate-runtime/global-dom-init/
  public-bundle-parity），3 个既有 harness 适配注册表初始化方式

assets/js/download-status.js

@@ -13,7 +13,8 @@
   'use strict';
 
   var DownloadStatus = {
-    init: function () {
+    init: function (root) {
+      this.root = root || document;
       this.initFilterHighlight();
       this.initCardHover();
     },
@@ -22,10 +23,13 @@
      * Animate filter button active state
      */
     initFilterHighlight: function () {
-      var filters = document.querySelectorAll('.aksrt-download-hero__filter');
+      var filters = this.root.nodeType === 1 && this.root.matches('.aksrt-download-hero__filter')
+        ? [this.root] : this.root.querySelectorAll('.aksrt-download-hero__filter');
       if (filters.length === 0) return;
 
       filters.forEach(function (btn) {
+        if (btn.dataset.aksrtDownloadHoverBound === '1') return;
+        btn.dataset.aksrtDownloadHoverBound = '1';
         btn.addEventListener('mouseenter', function () {
           btn.style.transform = 'translateY(-1px)';
         });
@@ -39,10 +43,13 @@
      * Card hover depth effect
      */
     initCardHover: function () {
-      var cards = document.querySelectorAll('.aksrt-download-card');
+      var cards = this.root.nodeType === 1 && this.root.matches('.aksrt-download-card')
+        ? [this.root] : this.root.querySelectorAll('.aksrt-download-card');
       if (cards.length === 0) return;
 
       cards.forEach(function (card) {
+        if (card.dataset.aksrtDownloadHoverBound === '1') return;
+        card.dataset.aksrtDownloadHoverBound = '1';
         card.addEventListener('mouseenter', function () {
           card.style.transform = 'translateY(-2px)';
         });
@@ -53,9 +60,7 @@
     },
   };
 
-  if (document.readyState === 'loading') {
-    document.addEventListener('DOMContentLoaded', function () { DownloadStatus.init(); });
-  } else {
-    DownloadStatus.init();
-  }
+  window.AksrtFrontend.register('aksrt-download-status', function (root) {
+    DownloadStatus.init(root);
+  });
 })();