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>

tests/widget-system/icon-picker-contract.test.cjs

@@ -50,7 +50,7 @@ test('widget and nav-menu icon fields render the shared picker', () => {
 
 test('picker JS composes the three value formats and loads the REST catalog', () => {
   const js = read('assets/js/admin-icon-picker.js');
-  for (const token of ['X-WP-Nonce', 'customsvg-', 'zibsvg-', '`fa ${group.id} fa-${name}`', 'data-jio-icon-picker', 'jio-icon-picker__value']) {
+  for (const token of ['X-WP-Nonce', 'customsvg-', 'jiosvg-', '`fa ${group.id} fa-${name}`', 'data-jio-icon-picker', 'jio-icon-picker__value']) {
     assert.match(js, new RegExp(token.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')));
   }
   assert.match(js, /DOMParser/, 'custom SVG is sanitized client side');
@@ -132,7 +132,7 @@ test('custom settings pages and standalone save paths speak the three icon forma
 
 test('nav menu icons render every format without legacy fa-prefix mangling', () => {
   const helper = read('inc/helpers/menu-decoration.php');
-  assert.match(helper, /str_starts_with\(\$icon_class, 'zibsvg-'\)/);
+  assert.match(helper, /str_starts_with\(\$icon_class, 'jiosvg-'\)/);
   assert.match(helper, /jio_icon_markup\(\$icon_class, 'icon mr3 menu-item-icon'\)/);
   assert.doesNotMatch(helper, /'<i class="' \. esc_attr\(\$icon_class\)/, 'no raw i-tag bypassing the unified helper');
 });
@@ -149,7 +149,7 @@ test('icon markup upgrades legacy FA4 values to FA5 and never emits the FA4 form
   assert.match(helper, /preg_replace\('\/\^fa\\s\+fa-\/i', '', \(string\) \$name\)/, 'icon keys normalize the legacy FA4 form');
 });
 
-test('brand icons render despite the zibll-legacy fa-fab double prefix', () => {
+test('brand icons render despite the legacy fa-fab double prefix', () => {
   const rule = /\.fa\.fab\{font-family:"Font Awesome 5 Brands";font-weight:400\}/;
   for (const file of ['assets/css/main.css', 'assets/css/admin-icon-picker.css', 'assets/admin/src/style.css']) {
     assert.match(read(file), rule, `${file} re-asserts the brand family`);