refactor: rename the theme brand and every identifier from AKSRT to Jio

Full-project rename. `git grep -i aksrt` is now empty apart from the
DBMigrator 3.3.0 changelog note that documents the rename itself.

Code identifiers
- PHP namespace AKSRT\ -> Jio\ (composer PSR-4 + 378 declarations)
- global constants AKSRT_* -> JIO_* (VERSION/DIR/URI, PAY_TYPE_*, CAPTCHA_*)
- procedural functions, hooks, options, meta keys, table names,
  cookies, query vars, ajax actions and nonces: aksrt_ -> jio_
- text domain aksrt -> jio; Theme Name -> Jio
- JS globals: aksrtData/aksrtAdminData/... -> jioData/jioAdminData/...,
  window.AKSRTCaptcha & friends -> window.JioCaptcha, Aksrt* -> Jio*
- Vue components Aks*.vue -> Jio*.vue (15 files renamed + imports)
- CSS classes/data-attrs/custom properties: aksrt- -> jio-
- REST namespace aksrt/v1 -> jio/v1 (incl. payment gateway callbacks)

Storage layer
- DB tables {prefix}aksrt_* -> {prefix}jio_*; SCHEMA_VERSION 3.2.0 -> 3.3.0
  so dbDelta creates the new names on install
- widget id_base aksrt_widget_* -> jio_widget_*
- uninstall.php drop list rebuilt from the actual migrator tables
  (dropped 3 stale entries, added the 17 missing ones)

Removed
- hardcoded https://api.aksrt.com/version.json default update endpoint;
  get_endpoint() now reads the 「更新端点」 setting and do_check() no-ops
  when it is empty

Files renamed: inc/helpers/aksrt-*.php -> jio-*.php (54),
assets/admin/src/components/form/Aks*.vue -> Jio*.vue (15).
Build artifacts regenerated: assets/css/build, assets/js/runtime,
assets/admin/build.

Verified: audit-psr4-paths errors=0, audit-admin-contracts errors=0
(warnings=56, unchanged baseline), 813/813 widget-system tests,
44/44 phpunit, php -l clean across all PHP.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/widget-system/posts-wrapper-contract.test.cjs

@@ -12,7 +12,7 @@ test('article list uses the reference widget container and keeps widget behavior
   const renderer = read('src/WidgetSystem/FrontendRenderer.php');
   const catalog = read('src/WidgetSystem/WidgetCatalog.php');
   assert.match(renderer, /\['user_card', 'author_card', 'tab_posts', 'posts'\]/);
-  assert.match(renderer, /\$classes = \['zib-widget-wrap', 'aksrt-' \. str_replace/);
+  assert.match(renderer, /\$classes = \['zib-widget-wrap', 'jio-' \. str_replace/);
   assert.match(renderer, /echo '<div class="widget-container"><div>'/);
   assert.match(renderer, /WidgetVisibility::device_class\(\$instance\)/);
   assert.match(renderer, /!empty\(\$instance\['sidebar_affix'\]\)/);
@@ -32,6 +32,6 @@ test('article list pagination shares the reference widget rules and obsolete tri
     '.widget-tab-post .posts-mini, .widget-main-post .posts-mini',
     '.widget-tab-post .posts-mini-con, .widget-main-post .posts-mini-con',
     '.widget-tab-post .item-meta .meta-pay, .widget-main-post .item-meta .meta-pay',
-    '.aksrt-posts-wrap :where(a, button, input, select, textarea, [tabindex]):focus-visible',
+    '.jio-posts-wrap :where(a, button, input, select, textarea, [tabindex]):focus-visible',
   ]) assert.ok(css.includes(token), `missing shared widget rule: ${token}`);
 });