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-single-render.php

@@ -196,7 +196,7 @@ if (!function_exists('jio_single_render_actions')) :
 		<div class="post-actions-wrap relative">
 			<div class="text-center post-actions">
 			<?php
-				$like_icon = function_exists('jio_icon_markup') ? jio_icon_markup('zibsvg-like') : '';
+				$like_icon = function_exists('jio_icon_markup') ? jio_icon_markup('jiosvg-like') : '';
 				$like_label = function_exists('jio_format_number') ? jio_format_number($like_count) : number_format_i18n($like_count);
 			if (!empty($settings['like_enabled'])) : ?>
 				<button type="button" class="action action-like<?php echo $is_liked ? ' actived' : ''; ?>" id="action-like" data-post-id="<?php echo esc_attr((string) $post_id); ?>" data-initial-active="<?php echo $is_liked ? '1' : '0'; ?>">
@@ -221,7 +221,7 @@ if (!function_exists('jio_single_render_actions')) :
 			<?php endif; ?>
 
 			<?php
-				$favorite_icon = function_exists('jio_icon_markup') ? jio_icon_markup('zibsvg-favorite') : '';
+				$favorite_icon = function_exists('jio_icon_markup') ? jio_icon_markup('jiosvg-favorite') : '';
 				$favorite_label = function_exists('jio_format_number') ? jio_format_number($favorite_count) : number_format_i18n($favorite_count);
 			if (!empty($settings['favorite_enabled'])) : ?>
 				<button type="button" class="action action-favorite<?php echo $is_favorited ? ' actived' : ''; ?>" id="action-favorite" data-post-id="<?php echo esc_attr((string) $post_id); ?>" data-initial-active="<?php echo $is_favorited ? '1' : '0'; ?>">
@@ -273,8 +273,8 @@ endif;
 
 if (!function_exists('jio_single_render_author_card')) :
 	/**
-	 * After-article author card (legacy zib_get_user_card_box parity:
-	 * show_button=false / show_img_bg=false / class="author").
+	 * After-article author card (show_button=false / show_img_bg=false /
+	 * class="author").
 	 *
 	 * @param array<string,mixed> $ctx Single context.
 	 */
@@ -308,7 +308,7 @@ if (!function_exists('jio_single_render_author_card')) :
 			'exclude'    => (int) get_the_ID(),
 		]);
 		?>
-		<div class="user-card zib-widget author">
+		<div class="user-card jio-widget-box author">
 			<div class="card-content mt10 relative">
 				<div class="user-content">
 					<div class="user-avatar"><?php echo $avatar_box; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped ?></div>
@@ -381,8 +381,8 @@ endif;
 
 if (!function_exists('jio_single_related_query_args')) :
 	/**
-	 * Build related-posts WP_Query args (legacy zib_posts_related parity:
-	 * category/topics/tag OR-terms, no current-post exclusion, meta orderby).
+	 * Build related-posts WP_Query args (category/topics/tag OR-terms,
+	 * no current-post exclusion, meta orderby).
 	 *
 	 * @param int                 $post_id  Post ID.
 	 * @param array<string,mixed> $settings Single display settings.
@@ -450,7 +450,7 @@ endif;
 
 if (!function_exists('jio_single_render_related')) :
 	/**
-	 * Related posts — legacy zib_posts_related parity (img/list/text).
+	 * Related posts (img/list/text).
 	 *
 	 * @param array<string,mixed> $ctx Single context.
 	 */
@@ -508,7 +508,7 @@ if (!function_exists('jio_single_render_related')) :
 			<div class="box-body notop">
 				<div class="title-theme"><?php echo esc_html($title); ?></div>
 			</div>
-			<div class="zib-widget">
+			<div class="jio-widget-box">
 				<?php if ($style === 'img') : ?>
 					<div class="swiper-container swiper-scroll">
 						<div class="swiper-wrapper"><?php echo $posts_html; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped ?></div>