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>

inc/helpers/user-center-renderers/sidebar-stats.php

@@ -34,8 +34,8 @@ $stats = [
 	],
 ];
 ?>
-<?php // 1:1 参考主题 zib_user_center_page_sidebar_statistics()：单张 zib-widget，四项 space-around 平铺。 ?>
-<div class="uc-sidebar-statistics mb10-sm mb20 flex ac jsa zib-widget padding-10 text-center" aria-label="<?php esc_attr_e('账号统计', 'jio'); ?>">
+<?php // 单张 jio-widget-box，四项 space-around 平铺。 ?>
+<div class="uc-sidebar-statistics mb10-sm mb20 flex ac jsa jio-widget-box padding-10 text-center" aria-label="<?php esc_attr_e('账号统计', 'jio'); ?>">
 	<?php foreach ($stats as $stat) : ?>
 		<a class="user-statistics-item" href="<?php echo esc_url((string) $stat['url']); ?>"<?php if (!empty($stat['tab'])) : ?> data-tab="<?php echo esc_attr((string) $stat['tab']); ?>"<?php endif; ?>><div class="em14"><?php echo esc_html(jio_cut_count((int) $stat['value'])); ?></div><div class="em09 opacity5 mt6"><?php echo esc_html((string) $stat['label']); ?></div></a>
 	<?php endforeach; ?>