chore(branding): remove leftover upstream theme identifiers

The theme was renamed Zibll/子比 → AKSRT → Jio, but upstream branding
survived the sweeps in CSS classes, the SVG sprite prefix, a persisted
widget field ID, JS events, admin Vue class names, test infrastructure
and docblocks.

Renames:
- zib-widget / zib-widget-wrap / zib-slider → jio-widget-box /
  jio-widget-box-wrap / jio-slider-box (jio-widget is taken by the modern
  widget shell, jio-box-* by the card primitives)
- zib-partners-scroll + zps-* → jio-partners-scroll + jps-*
- zib-combo-info-card + zci-* → jio-combo-info-card + jci-*
- zibsvg- → jiosvg-, including the exported picker helpers and the
  fa-zibsvg- family-prefix guard
- zibpay_type → pay_type; the dual-read fallback in PostQuery collapses
  to a single key
- [zibajax="submit"] dropped (no PHP emitter); zib_ajax.success →
  jio_ajax.success
- aks-* admin Vue classes → jio-*
- zib_palette() → palette()

User-facing vendor traces are gone: the floating "more" button default no
longer ships a zibll.com link or 子比主题 marketing copy, the notice
widget ships no preset promo entries, and the four 官网教程 links are
removed from the post-list admin schema.

Test infrastructure renamed to neutral names (docker-compose.reference.yml,
Caddyfile, article-baseline.json, modern-widgets-contract.test.cjs) with
their DB/volume/env/slug identifiers following.

Kept intentionally, documented in tests/fixtures/README.md: the golden
fixture reference fingerprint (a SHA-256 record of an external directory,
read by validate-widget-golden / generate-widget-golden-fixture /
audit-widget-system), the doesNotMatch guards that prove the old tokens are
gone, and the reference theme's own meta key in the visual fixtures.

No backward-compat or data migration: saved widget configs holding old
icon keys or the old field ID silently lose them, per the project's
rewrite-over-compatibility rule.

Verified: 132/132 node contract tests, php tests/widget-system/run.php
(146 assertions), audit-admin-contracts, audit-psr4-paths and
validate-widget-golden all green; tracked bundles regenerated and in sync.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

assets/js/core/ajax-list.js

@@ -357,8 +357,8 @@
     if (link.closest("[data-jio-ajax-list='off']")) return;
     // The canonical pagination engine exclusively owns these controls.
     if (link.closest("[data-jio-pagination], .jio-comment-pagination")) return;
-    // 排序菜单与 pane 触发器是 runtime post_ajax 管线（zib_ajax_option_menu /
-    // zib_index_tab 契约）的专属控件，这里不能并行处理造成双请求。
+    // 排序菜单与 pane 触发器是 runtime post_ajax 管线（option-menu /
+    // index-tab 契约）的专属控件，这里不能并行处理造成双请求。
     if (link.closest(".ajax-option, .post_ajax_trigger")) return;
 
     var href = link.getAttribute("href") || link.getAttribute("ajax-href") || link.getAttribute("data-jio-ajax-url");

assets/js/core/pagination.js

@@ -51,7 +51,7 @@
       }
 
       // 文章骨架：与 runtime/main.js 的 .ajax-next 处理器、jio_render_placeholder()
-      // 同源同款（1:1 对齐参考主题 zib_get_post_placeholder）。刻意不写 ajax-item：
+      // 同源同款（1:1 对齐 post placeholder 契约）。刻意不写 ajax-item：
       // 否则会被 inject() / find('.ajax-item') 当成真实条目删除或定位。
       var CARD_ITEM =
         '<div class="posts-item card"><div class="item-thumbnail">' +