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/homepage/header-components.php

@@ -114,7 +114,7 @@ if (!function_exists('jio_header_slide_is_show')) {
 			return false;
 		}
 
-		// Zibll only displays this component on the first archive page.
+		// This component only displays on the first archive page.
 		if ((int) $wp_query->get('paged') > 1) {
 			return false;
 		}
@@ -441,9 +441,9 @@ if (!function_exists('jio_header_slide')) {
 			$card_options = wp_parse_args((array) ($args['header_slider_card_option'] ?? []), [
 				'icon_radius4' => false, 'show_widget_bg' => false, 'cards' => [],
 			]);
-			// legacy (Zibll): with module background the card shrinks to
-			// padding-10 inside a .zib-widget wrapper (.jio-panel here); the
-			// bg-less variant stretches each card in a .flex1 column.
+			// With module background the card shrinks to padding-10 inside a
+			// .jio-widget-box wrapper (.jio-panel here); the bg-less variant
+			// stretches each card in a .flex1 column.
 			$show_bg = !empty($card_options['show_widget_bg']);
 			$items = '';
 			foreach ((array) $card_options['cards'] as $card) {