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/single-cover-height-contract.test.cjs

@@ -13,8 +13,8 @@ const test = require('node:test');
 const root = path.resolve(__dirname, '..', '..');
 const read = (file) => fs.readFileSync(path.join(root, file), 'utf8');
 
-const singleRender = read('inc/helpers/aksrt-single-render.php');
-const sliderHelper = read('inc/helpers/aksrt-slider.php');
+const singleRender = read('inc/helpers/jio-single-render.php');
+const sliderHelper = read('inc/helpers/jio-slider.php');
 
 test('single cover: image mode keeps the calc(scale% + 50px) height', () => {
   assert.match(
@@ -51,7 +51,7 @@ test('single cover: slide mode reserves the same +50px via the slider helper', (
   assert.match(
     singleRender,
     /\$slider_args\['scale_extra'\] = '50px';/,
-    '比例高度分支必须向 aksrt_render_slider 传 scale_extra=50px'
+    '比例高度分支必须向 jio_render_slider 传 scale_extra=50px'
   );
   assert.match(
     singleRender,
@@ -74,8 +74,8 @@ test('single cover: slide mode reserves the same +50px via the slider helper', (
 test('single cover: the dead static slide fallback is gone', () => {
   assert.doesNotMatch(
     singleRender,
-    /function_exists\('aksrt_render_slider'\)/,
-    'aksrt_render_slider 由 bootstrap 无条件加载，不得保留 function_exists 双路判断'
+    /function_exists\('jio_render_slider'\)/,
+    'jio_render_slider 由 bootstrap 无条件加载，不得保留 function_exists 双路判断'
   );
   assert.doesNotMatch(
     singleRender,
@@ -107,7 +107,7 @@ test('video cover: the player video fills and center-crops like the image cover'
   const player = read('assets/js/video-player.js');
   assert.match(
     player,
-    /\.aksrt-video video\{display:block;width:100%;height:100%;object-fit:cover;\}/,
+    /\.jio-video video\{display:block;width:100%;height:100%;object-fit:cover;\}/,
     '视频必须铺满封面比例盒并居中裁切'
   );
   assert.doesNotMatch(
@@ -180,7 +180,7 @@ test('resource singles get the cover leaf versioned, never via the aggregate @im
   );
   assert.match(
     enqueue,
-    /'aksrt-single-post-cover'/,
+    /'jio-single-post-cover'/,
     'cover leaf 句柄与文章分支命名保持一致'
   );
 });