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>

src/WidgetSystem/PostQuery.php

@@ -29,13 +29,13 @@ final class PostQuery {
 			$args['paged'] = 1;
 		}
 
-		// The modern post widgets use Zibll's signed `cat` syntax. Legacy
+		// The modern post widgets use the signed `cat` syntax. Legacy
 		// category_ids remains available only to the unrelated generic posts
 		// widgets; a tab segment must never fall back to it.
 		$is_reference_segment = array_key_exists('cat', $segment);
 		if (array_key_exists('cat', $config)) {
 			// WP_Query's `cat` expands included parents to descendants and
-			// applies negative IDs with the same reference-theme semantics.
+			// applies negative IDs as exclusions.
 			$categories = self::signed_ids((string) $config['cat']);
 			if ($categories) {
 				$args['cat'] = implode(',', $categories);
@@ -64,8 +64,7 @@ final class PostQuery {
 			]];
 		}
 		self::apply_order($args, (string) ($config['orderby'] ?? 'date'), (string) ($config['order'] ?? 'DESC'));
-		$pay = array_key_exists('zibpay_type', $config) ? $config['zibpay_type'] : ($config['pay_type'] ?? '');
-		self::apply_pay_type($args, $pay);
+		self::apply_pay_type($args, $config['pay_type'] ?? '');
 		return $args;
 	}