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/css/frontend/single-post/cover.css

@@ -94,7 +94,7 @@
 
 
 /* ===== Video footer (legacy single-video-footer) ===== */
-/* 内边距沿用 legacy 契约 .single-video-footer{padding:15px}（与 zibll 一致），
+/* 内边距沿用 legacy 契约 .single-video-footer{padding:15px}，
    面包屑在 flex jsb at 行首，不再额外包装。 */
 .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;

assets/css/frontend/single-post/related-toc.css

@@ -383,8 +383,8 @@ html.dark .article-end-separator span {
 
 
 
-/* ===== Zibll .zib-widget base (正文下方卡片堆栈依赖) ===== */
-.zib-widget {
+/* ===== .jio-widget-box base (正文下方卡片堆栈依赖) ===== */
+.jio-widget-box {
     clear: both;
     background-color: var(--main-bg-color);
     padding: 15px;
@@ -392,7 +392,7 @@ html.dark .article-end-separator span {
     border-radius: var(--main-radius);
     margin-bottom: 20px;
 }
-.zib-widget.nobottom.notop {
+.jio-widget-box.nobottom.notop {
     padding-top: 0;
     padding-bottom: 0;
 }