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/tab-posts-render-behavior.test.cjs

@@ -140,16 +140,16 @@ test('list margin defaults inherit the site setting while an explicit widget fal
 
 test('multi-column frontend output uses the reference widget wrapper and carries layout variables', () => {
   const wrapper = render().frontend_wrapper;
-  assert.match(wrapper, /class="zib-widget-wrap aksrt-tab-posts-wrap"/);
-  assert.match(wrapper, /data-aksrt-widget="tab_posts" data-widget-id="aksrt_widget_tab_posts-4"/);
-  assert.match(wrapper, /--aksrt-widget-space-top:8px/);
-  assert.match(wrapper, /--aksrt-widget-space-m-bottom:10px/);
-  assert.match(wrapper, /--aksrt-widget-bg-light:#ffffff/);
-  assert.match(wrapper, /--aksrt-widget-bg-dark:#111111/);
+  assert.match(wrapper, /class="zib-widget-wrap jio-tab-posts-wrap"/);
+  assert.match(wrapper, /data-jio-widget="tab_posts" data-widget-id="jio_widget_tab_posts-4"/);
+  assert.match(wrapper, /--jio-widget-space-top:8px/);
+  assert.match(wrapper, /--jio-widget-space-m-bottom:10px/);
+  assert.match(wrapper, /--jio-widget-bg-light:#ffffff/);
+  assert.match(wrapper, /--jio-widget-bg-dark:#111111/);
   assert.match(wrapper, /widget-container/);
   assert.match(wrapper, /class="widget-content"/);
   assert.match(wrapper, /class="widget-tab-post style-mini/);
-  assert.doesNotMatch(wrapper, /aksrt-widget__inner container|<aside>|<\/aside>/);
+  assert.doesNotMatch(wrapper, /jio-widget__inner container|<aside>|<\/aside>/);
 
   const frontend = read('src/WidgetSystem/FrontendRenderer.php');
   const routeStart = frontend.indexOf("if (in_array($definition->slug(), ['user_card', 'author_card', 'tab_posts', 'posts']");