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/pages/empty-state.css

@@ -1,8 +1,8 @@
 /* ============================================================
- * 文章归档（page-archives.php + [aksrt_archive] 短代码）
- * Phase 10 视觉收口：此前 .aksrt-archives 无样式。
+ * 文章归档（page-archives.php + [jio_archive] 短代码）
+ * Phase 10 视觉收口：此前 .jio-archives 无样式。
  * ============================================================ */
-.aksrt-archives__year {
+.jio-archives__year {
   font-size: 1.5rem;
   font-weight: 700;
   color: var(--color-ink);
@@ -11,24 +11,24 @@
   border-bottom: 2px solid var(--color-line);
 }
 
-.aksrt-archives__year:first-child {
+.jio-archives__year:first-child {
   margin-top: 0;
 }
 
-.aksrt-archives__month {
+.jio-archives__month {
   font-size: 0.95rem;
   font-weight: 600;
   color: var(--color-ink-3, #666);
   margin: 16px 0 8px;
 }
 
-.aksrt-archives__list {
+.jio-archives__list {
   list-style: none;
   margin: 0 0 8px;
   padding: 0;
 }
 
-.aksrt-archives__item {
+.jio-archives__item {
   display: flex;
   align-items: baseline;
   gap: 12px;
@@ -36,33 +36,33 @@
   border-bottom: 1px dashed var(--color-line);
 }
 
-.aksrt-archives__date {
+.jio-archives__date {
   flex-shrink: 0;
   font-variant-numeric: tabular-nums;
   font-size: 0.8125rem;
   color: var(--color-ink-4, #999);
 }
 
-.aksrt-archives__link {
+.jio-archives__link {
   color: var(--color-ink);
   text-decoration: none;
   transition: color 0.15s ease;
 }
 
-.aksrt-archives__link:hover {
+.jio-archives__link:hover {
   color: var(--color-primary);
 }
 
-.aksrt-archives--empty {
+.jio-archives--empty {
   padding: 24px;
   text-align: center;
   color: var(--color-ink-4, #999);
 }
 
 /* ============================================================
- * 个人资料卡短代码（[aksrt_profile]）
+ * 个人资料卡短代码（[jio_profile]）
  * ============================================================ */
-.aksrt-profile-card {
+.jio-profile-card {
   display: flex;
   gap: 14px;
   align-items: flex-start;
@@ -72,55 +72,55 @@
   background: var(--surface-1, #fff);
 }
 
-.aksrt-profile-card--guest {
+.jio-profile-card--guest {
   flex-direction: column;
   align-items: flex-start;
   gap: 10px;
 }
 
-.aksrt-profile-card__avatar img {
+.jio-profile-card__avatar img {
   width: 64px;
   height: 64px;
   border-radius: 50%;
   object-fit: cover;
 }
 
-.aksrt-profile-card__body {
+.jio-profile-card__body {
   flex: 1;
   min-width: 0;
 }
 
-.aksrt-profile-card__name {
+.jio-profile-card__name {
   font-size: 1rem;
   font-weight: 600;
   color: var(--color-ink);
   text-decoration: none;
 }
 
-.aksrt-profile-card__name:hover {
+.jio-profile-card__name:hover {
   color: var(--color-primary);
 }
 
-.aksrt-profile-card__bio {
+.jio-profile-card__bio {
   margin: 4px 0 8px;
   font-size: 0.8125rem;
   color: var(--color-ink-3, #666);
   line-height: 1.5;
 }
 
-.aksrt-profile-card__stats {
+.jio-profile-card__stats {
   display: flex;
   gap: 18px;
 }
 
-.aksrt-profile-card__stat {
+.jio-profile-card__stat {
   display: flex;
   flex-direction: column;
   font-size: 0.75rem;
   color: var(--color-ink-4, #999);
 }
 
-.aksrt-profile-card__stat strong {
+.jio-profile-card__stat strong {
   font-size: 1.05rem;
   color: var(--color-ink);
   line-height: 1.2;