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>

assets/js/admin-post-extension.js

@@ -1,11 +1,11 @@
 (function ($) {
   'use strict';
 
-  var root = document.querySelector('[data-aksrt-post-extension]');
+  var root = document.querySelector('[data-jio-post-extension]');
   if (!root || !window.wp || !wp.media) return;
 
   function openMedia(button) {
-    var wrap = button.closest('.aksrt-post-extension__upload');
+    var wrap = button.closest('.jio-post-extension__upload');
     var input = wrap && wrap.querySelector('[data-media-input]');
     if (!input) return;
 
@@ -58,7 +58,7 @@
   }
 
   function syncVideoDependencies() {
-    var input = root.querySelector('input[name="aksrt_post_extension[featured_video]"]');
+    var input = root.querySelector('input[name="jio_post_extension[featured_video]"]');
     root.querySelectorAll('[data-video-dependent]').forEach(function (field) {
       field.hidden = !input || !input.value.trim();
     });
@@ -75,7 +75,7 @@
     var clear = event.target.closest('[data-media-clear]');
     if (clear) {
       event.preventDefault();
-      var wrap = clear.closest('.aksrt-post-extension__upload');
+      var wrap = clear.closest('.jio-post-extension__upload');
       var input = wrap && wrap.querySelector('[data-media-input]');
       if (input) {
         input.value = '';