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/css/frontend/comment-tools.css

@@ -1,5 +1,5 @@
 /**
- * AKSRT Comment Tools
+ * Jio Comment Tools
  *
  * 评论相关样式（工具栏下拉、内容中的代码块/图片等）全部由 vendor
  * legacy main.min.css 提供，本文件不复制以免覆盖正版样式。
@@ -7,7 +7,7 @@
  */
 
 /* ========== 投稿页面增强 ========== */
-.aksrt-submit-form__cover-preview {
+.jio-submit-form__cover-preview {
   width: 100%;
   max-width: 400px;
   aspect-ratio: 16 / 9;
@@ -20,18 +20,18 @@
   justify-content: center;
 }
 
-.aksrt-submit-form__cover-preview img {
+.jio-submit-form__cover-preview img {
   width: 100%;
   height: 100%;
   object-fit: cover;
 }
 
-.aksrt-submit-form__cover-placeholder {
+.jio-submit-form__cover-placeholder {
   color: var(--text-tertiary, #8a909c);
   font-size: 13px;
 }
 
-.aksrt-submit-form__field-toggle {
+.jio-submit-form__field-toggle {
   display: flex;
   align-items: center;
   gap: 8px;
@@ -40,14 +40,14 @@
   color: var(--text-secondary, #666);
 }
 
-.aksrt-submit-form__word-count {
+.jio-submit-form__word-count {
   margin-top: 4px;
   font-size: 12px;
   color: var(--text-tertiary, #8a909c);
   text-align: right;
 }
 
-.aksrt-submit-form__leave-warning {
+.jio-submit-form__leave-warning {
   position: fixed;
   bottom: 20px;
   left: 50%;
@@ -63,14 +63,14 @@
 }
 
 /* ========== Post Share Buttons ========== */
-.aksrt-share-bar {
+.jio-share-bar {
   display: flex;
   align-items: center;
   gap: 8px;
   flex-wrap: wrap;
 }
 
-.aksrt-share-btn {
+.jio-share-btn {
   display: inline-flex;
   align-items: center;
   gap: 6px;
@@ -85,26 +85,26 @@
   transition: all 0.2s;
 }
 
-.aksrt-share-btn:hover {
+.jio-share-btn:hover {
   border-color: var(--color-primary);
   color: var(--color-primary);
   background: var(--color-primary-soft, rgba(240, 68, 148, 0.06));
 }
 
-.aksrt-share-btn.is-copied {
+.jio-share-btn.is-copied {
   border-color: #52c41a;
   color: #52c41a;
   background: #f6ffed;
 }
 
-.aksrt-share-btn--weibo:hover { border-color: #e6162d; color: #e6162d; }
-.aksrt-share-btn--qq:hover { border-color: #12b7f5; color: #12b7f5; }
-.aksrt-share-btn--wechat:hover { border-color: #07c160; color: #07c160; }
-.aksrt-share-btn--telegram:hover { border-color: #26a5e4; color: #26a5e4; }
-.aksrt-share-btn--twitter:hover { border-color: #1da1f2; color: #1da1f2; }
+.jio-share-btn--weibo:hover { border-color: #e6162d; color: #e6162d; }
+.jio-share-btn--qq:hover { border-color: #12b7f5; color: #12b7f5; }
+.jio-share-btn--wechat:hover { border-color: #07c160; color: #07c160; }
+.jio-share-btn--telegram:hover { border-color: #26a5e4; color: #26a5e4; }
+.jio-share-btn--twitter:hover { border-color: #1da1f2; color: #1da1f2; }
 
 /* Quick quote button */
-.aksrt-quick-quote {
+.jio-quick-quote {
   position: fixed;
   padding: 4px 12px;
   background: var(--color-primary);
@@ -118,13 +118,13 @@
   transition: background 0.2s;
 }
 
-.aksrt-quick-quote:hover {
+.jio-quick-quote:hover {
   background: var(--color-primary-hover, #40a9ff);
 }
 
 /* TOC active state */
-.aksrt-doc-toc__item.is-active > a,
-.aksrt-doc-toc__item a.is-active {
+.jio-doc-toc__item.is-active > a,
+.jio-doc-toc__item a.is-active {
   color: var(--color-primary);
   font-weight: 600;
   border-left-color: var(--color-primary);