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/jio-rewards.php

@@ -24,7 +24,7 @@ if (!function_exists('jio_get_rewards_button')) {
 		}
 		$settings = \Jio\Settings\Settings::get_post_page_settings();
 		$label = (string) ($settings['rewards_btn_text'] ?? __('赞赏', 'jio'));
-		$icon = function_exists('jio_icon_markup') ? jio_icon_markup('zibsvg-money') : '';
+		$icon = function_exists('jio_icon_markup') ? jio_icon_markup('jiosvg-money') : '';
 		$template_id = 'jio-reward-template-' . $user_id . '-' . $post_id;
 		return sprintf(
 			'<button type="button" class="%1$s jio-reward-open" data-jio-reward-open data-template-id="%2$s" data-user-id="%3$d" data-post-id="%4$d">%5$s<text>%6$s</text></button>',
@@ -62,8 +62,8 @@ if (!function_exists('jio_render_rewards_template_for_user')) {
 		$recipient = get_userdata($user_id);
 		$template_id = 'jio-reward-template-' . $user_id . '-' . $post_id;
 		$title = (string) ($settings['rewards_text'] ?? __('赞赏', 'jio'));
-		$money_icon = function_exists('jio_icon_markup') ? jio_icon_markup('zibsvg-money') : '<i class="fa fas fa-money-bill-wave" aria-hidden="true"></i>';
-		$close_icon = function_exists('jio_icon_markup') ? jio_icon_markup('zibsvg-close', 'ic-close') : '<i class="fa fas fa-times" aria-hidden="true"></i>';
+		$money_icon = function_exists('jio_icon_markup') ? jio_icon_markup('jiosvg-money') : '<i class="fa fas fa-money-bill-wave" aria-hidden="true"></i>';
+		$close_icon = function_exists('jio_icon_markup') ? jio_icon_markup('jiosvg-close', 'ic-close') : '<i class="fa fas fa-times" aria-hidden="true"></i>';
 		?>
 		<template id="<?php echo esc_attr($template_id); ?>" data-user-id="<?php echo (int) $user_id; ?>" data-post-id="<?php echo (int) $post_id; ?>">
 			<div class="modal-colorful-header colorful-bg jb-blue">