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>

single.php

@@ -2,9 +2,9 @@
 /**
  * Single post template — legacy-style shell.
  *
- * Composition lives in inc/helpers/aksrt-single.php.
+ * Composition lives in inc/helpers/jio-single.php.
  *
- * @package AKSRT
+ * @package Jio
  */
 
 defined('ABSPATH') || exit;
@@ -15,11 +15,11 @@ while (have_posts()) :
 	the_post();
 
 	$post_id = (int) get_the_ID();
-	$ctx = function_exists('aksrt_single_build_context')
-		? aksrt_single_build_context($post_id)
+	$ctx = function_exists('jio_single_build_context')
+		? jio_single_build_context($post_id)
 		: ['show_aside' => false, 'settings' => []];
 
-	if (function_exists('aksrt_single_is_docs_page') && aksrt_single_is_docs_page($post_id)) {
+	if (function_exists('jio_single_is_docs_page') && jio_single_is_docs_page($post_id)) {
 		get_header();
 		get_template_part('templates/pages/page-documentnav');
 		get_footer();
@@ -33,7 +33,7 @@ while (have_posts()) :
 	?>
 
 	<?php if (!empty($settings['reading_progress'])) : ?>
-		<div id="reading-progress-global" class="reading-progress-bar" role="progressbar" aria-label="<?php esc_attr_e('阅读进度', 'aksrt'); ?>" aria-valuemin="0" aria-valuemax="100" aria-valuenow="0"></div>
+		<div id="reading-progress-global" class="reading-progress-bar" role="progressbar" aria-label="<?php esc_attr_e('阅读进度', 'jio'); ?>" aria-valuemin="0" aria-valuemax="100" aria-valuenow="0"></div>
 	<?php endif; ?>
 
 	<?php if (is_active_sidebar('single_top_fluid')) : ?>
@@ -50,8 +50,8 @@ while (have_posts()) :
 				<?php endif; ?>
 
 				<?php
-				if (function_exists('aksrt_single')) {
-					aksrt_single($ctx);
+				if (function_exists('jio_single')) {
+					jio_single($ctx);
 				}
 				?>
 
@@ -66,8 +66,8 @@ while (have_posts()) :
 		</div>
 
 		<?php
-		if (function_exists('aksrt_single_render_aside')) {
-			aksrt_single_render_aside($ctx);
+		if (function_exists('jio_single_render_aside')) {
+			jio_single_render_aside($ctx);
 		}
 		?>
 	</main>