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>

tools/wp-cli-visual-fixtures.php

@@ -1,6 +1,6 @@
 <?php
 /**
- * Reversible WP-CLI visual fixtures for Jio/Zibll comparison.
+ * Reversible WP-CLI visual fixtures for reference comparison.
  *
  * Usage:
  *   wp eval-file wp-content/themes/Jio/tools/wp-cli-visual-fixtures.php create
@@ -17,7 +17,7 @@ if (!defined('WP_CLI') || !WP_CLI) {
 
 $fixture_action = sanitize_key((string) ($args[0] ?? ''));
 $fixture_option = 'jio_visual_fixture_manifest_v1';
-$fixture_prefix = 'jio_zibll_v1_';
+$fixture_prefix = 'jio_visual_v1_';
 $fixture_theme_dir = dirname(__DIR__);
 $fixture_json = $fixture_theme_dir . '/tests/fixtures/widget-golden-v1.json';
 
@@ -181,7 +181,7 @@ try {
 			'post_status'  => 'publish',
 			'post_type'    => 'post',
 			'post_author'  => (int) ($user_map[(int) ($source['author'] ?? 0)] ?? 1),
-			'post_excerpt' => '用于 Jio 与 Zibll 同内容视觉比较的固定摘要。',
+			'post_excerpt' => '用于参考主题与 Jio 同内容视觉比较的固定摘要。',
 			'post_content' => '<h2>视觉基线标题</h2><p>固定正文内容，用于检查排版、目录、付费状态和响应式布局。</p>',
 		], true);
 		if (is_wp_error($post_id)) {