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/layout.css

@@ -18,8 +18,8 @@
 
 /* 用户中心（双栏）铺满视口：左栏 320 + 间距 20 + 右栏需要横向空间，被
  * 阅读宽度收窄会在左右两侧留下大片空白。只有 page-profile.php 的 main 带
- * .aksrt-profile（公开主页的该类只打在 body 上），因此不会误伤其它路由。 */
-.site-main.content-shell.aksrt-profile {
+ * .jio-profile（公开主页的该类只打在 body 上），因此不会误伤其它路由。 */
+.site-main.content-shell.jio-profile {
   max-width: 100%;
   box-sizing: border-box;
 }
@@ -27,7 +27,7 @@
 /* 公开主页是单栏，继续沿用后台「内容最大宽度」。顶部多功能组件位于
  * main 之前；main 的通用 32/40px 上内边距会把资料卡与组件人为拉开，
  * 这里仅对公开主页清除该段重复空白。 */
-.site-main.content-shell.aksrt-user-home {
+.site-main.content-shell.jio-user-home {
   max-width: var(--container, 1440px);
   padding-top: 0;
   box-sizing: border-box;
@@ -258,11 +258,11 @@ body.category .site-main {
   line-height: 1.42857143;
 }
 
-.page-cover.aksrt-panel {
+.page-cover.jio-panel {
   padding: 0 0 calc(25% + 80px);
 }
 
-.aksrt-admin-quicklink {
+.jio-admin-quicklink {
   display: inline-flex;
   align-items: center;
   gap: 8px;
@@ -278,7 +278,7 @@ body.category .site-main {
   font-weight: 600;
 }
 
-.aksrt-admin-quicklink:hover {
+.jio-admin-quicklink:hover {
   color: var(--color-primary);
   border-color: var(--color-primary);
   background: var(--color-primary-soft, rgba(59, 130, 246, 0.08));
@@ -313,13 +313,13 @@ body.category .site-main {
    全站只有一套加载语言。 */
 
 @media (max-width: 767px) {
-  .aksrt-admin-quicklink {
+  .jio-admin-quicklink {
     width: fit-content;
   }
 }
 
 /* ========== AJAX 分页（加载更多 / 无限滚动） ========== */
-.aksrt-pagination-ajax {
+.jio-pagination-ajax {
   display: flex;
   flex-direction: column;
   align-items: center;
@@ -327,7 +327,7 @@ body.category .site-main {
   margin: 40px 0 8px;
 }
 
-.aksrt-load-more-btn {
+.jio-load-more-btn {
   min-width: 180px;
   height: 44px;
   padding: 0 32px;
@@ -345,17 +345,17 @@ body.category .site-main {
   gap: 8px;
 }
 
-.aksrt-load-more-btn:hover {
+.jio-load-more-btn:hover {
   border-color: var(--color-primary);
   color: var(--color-primary);
 }
 
-.aksrt-load-more-btn:disabled {
+.jio-load-more-btn:disabled {
   opacity: 0.5;
   pointer-events: none;
 }
 
-.aksrt-loading-indicator {
+.jio-loading-indicator {
   display: none;
   align-items: center;
   gap: 8px;
@@ -363,11 +363,11 @@ body.category .site-main {
   color: var(--color-ink-4);
 }
 
-.aksrt-loading-indicator i {
+.jio-loading-indicator i {
   font-size: 16px;
 }
 
-.aksrt-scroll-sentinel {
+.jio-scroll-sentinel {
   width: 100%;
   height: 1px;
   pointer-events: none;