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/footer/part.css

@@ -1,11 +1,11 @@
 /* ============================================================
- * AKSRT Footer utilities — float buttons start + device helpers
+ * Jio Footer utilities — float buttons start + device helpers
  * Main template_1 shell: shell.css
  * Tabbar / float details continue below.
  * ============================================================ */
 
 :root {
-    --aksrt-footer-tabbar-height: 49px;
+    --jio-footer-tabbar-height: 49px;
 }
 
 /* Device visibility utility classes */
@@ -28,7 +28,7 @@
     left: 0;
     right: 0;
     z-index: 1035;
-    min-height: var(--aksrt-footer-tabbar-height);
+    min-height: var(--jio-footer-tabbar-height);
     background: var(--blur-bg);
     border-top: 1px solid var(--color-line-soft);
     padding: 0 0 env(safe-area-inset-bottom, 0px);
@@ -64,7 +64,7 @@
 
 .footer-tabbar-placeholder {
     display: none;
-    height: calc(var(--aksrt-footer-tabbar-height) + env(safe-area-inset-bottom, 0px));
+    height: calc(var(--jio-footer-tabbar-height) + env(safe-area-inset-bottom, 0px));
 }
 
 @media (max-width: 767px) {
@@ -79,7 +79,7 @@
     /* 有 tabbar 时页脚需要额外底部间距 */
     .footer,
     .site-footer {
-        padding-bottom: calc(var(--aksrt-footer-tabbar-height) + env(safe-area-inset-bottom, 0px));
+        padding-bottom: calc(var(--jio-footer-tabbar-height) + env(safe-area-inset-bottom, 0px));
     }
 }