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)

src/Content/PayHelpers.php

@@ -224,7 +224,7 @@ trait PayHelpers {
                 'payable'         => round($payable, 2),
                 'rebate_price'    => round($rebate_price, 2),
             ],
-            // zibll: points_deduction runtime hard-off; card_pass not a content payment method.
+            // legacy: points_deduction runtime hard-off; card_pass not a content payment method.
             'points_deduction_allowed' => function_exists('aksrt_is_allow_points_deduction')
                 ? (bool) aksrt_is_allow_points_deduction('content')
                 : false,
@@ -271,7 +271,7 @@ trait PayHelpers {
             ? aksrt_get_user_pay_price($post, $user_id)
             : ['amount' => 0.0, 'modo' => '0', 'pay_limit' => 0, 'vip_level' => 0, 'is_free' => true, 'base' => 0.0];
 
-        // Free daily quota overbuy: override amount, ignore VIP discount (zibll).
+        // Free daily quota overbuy: override amount, ignore VIP discount (legacy).
         if ($price_type === 'download_limit_over') {
             $over = max(0.0, (float) ($meta['download_limit_over_price'] ?? 0));
             if ($over <= 0) {