chore(branding): remove leftover upstream theme identifiers

The theme was renamed Zibll/子比 → AKSRT → Jio, but upstream branding
survived the sweeps in CSS classes, the SVG sprite prefix, a persisted
widget field ID, JS events, admin Vue class names, test infrastructure
and docblocks.

Renames:
- zib-widget / zib-widget-wrap / zib-slider → jio-widget-box /
  jio-widget-box-wrap / jio-slider-box (jio-widget is taken by the modern
  widget shell, jio-box-* by the card primitives)
- zib-partners-scroll + zps-* → jio-partners-scroll + jps-*
- zib-combo-info-card + zci-* → jio-combo-info-card + jci-*
- zibsvg- → jiosvg-, including the exported picker helpers and the
  fa-zibsvg- family-prefix guard
- zibpay_type → pay_type; the dual-read fallback in PostQuery collapses
  to a single key
- [zibajax="submit"] dropped (no PHP emitter); zib_ajax.success →
  jio_ajax.success
- aks-* admin Vue classes → jio-*
- zib_palette() → palette()

User-facing vendor traces are gone: the floating "more" button default no
longer ships a zibll.com link or 子比主题 marketing copy, the notice
widget ships no preset promo entries, and the four 官网教程 links are
removed from the post-list admin schema.

Test infrastructure renamed to neutral names (docker-compose.reference.yml,
Caddyfile, article-baseline.json, modern-widgets-contract.test.cjs) with
their DB/volume/env/slug identifiers following.

Kept intentionally, documented in tests/fixtures/README.md: the golden
fixture reference fingerprint (a SHA-256 record of an external directory,
read by validate-widget-golden / generate-widget-golden-fixture /
audit-widget-system), the doesNotMatch guards that prove the old tokens are
gone, and the reference theme's own meta key in the visual fixtures.

No backward-compat or data migration: saved widget configs holding old
icon keys or the old field ID silently lose them, per the project's
rewrite-over-compatibility rule.

Verified: 132/132 node contract tests, php tests/widget-system/run.php
(146 assertions), audit-admin-contracts, audit-psr4-paths and
validate-widget-golden all green; tracked bundles regenerated and in sync.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

README.md

@@ -167,7 +167,7 @@ WordPress 后台左侧 **Admin Bar** → ⚡ **Jio 主题设置**
 ### 4. 推广、邀请与佣金（用户中心 → 收益）
 
 - **推广链接**：用户中心「收益」页展示带 `?ref=` 的推广链接、二维码（可下载 PNG）与推广海报（按「推广返佣」设置中的海报文案生成）。归因模式（首触/末触）在「支付&付费 → 推广返佣 → 推广归因模式」配置。
-- **一次性邀请码**：后台「用户 → 邀请码管理」三视图运营页——列表（状态筛选/搜索/批量删除/排序/分页/点击复制）、添加（系统自动生成：数量/标识/四类奖励[经验值、积分、余额、VIP]/高级选项自定义位数；或 Zibll 兼容文本导入：一行一码 `邀请码 奖励 标识`，奖励参数串 `points=20&balance=30&vip=1&vip_time=5&level_integral=100`，分隔符可自定义）、导出（状态筛选 + 文本文档[可回流导入]/Excel表格 双格式）。注册门控模式在「用户&互动 → 登录注册 → 邀请码注册」。消费为原子操作，并发注册不会超发；开启注册验证时奖励延迟到邮箱验证后发放。
+- **一次性邀请码**：后台「用户 → 邀请码管理」三视图运营页——列表（状态筛选/搜索/批量删除/排序/分页/点击复制）、添加（系统自动生成：数量/标识/四类奖励[经验值、积分、余额、VIP]/高级选项自定义位数；或行格式文本导入：一行一码 `邀请码 奖励 标识`，奖励参数串 `points=20&balance=30&vip=1&vip_time=5&level_integral=100`，分隔符可自定义）、导出（状态筛选 + 文本文档[可回流导入]/Excel表格 双格式）。注册门控模式在「用户&互动 → 登录注册 → 邀请码注册」。消费为原子操作，并发注册不会超发；开启注册验证时奖励延迟到邮箱验证后发放。
 - **佣金**：订单支付成功后按推广者等级分档比例记录到佣金账本，经「结算观察期」后自动结算入钱包，支持提现与退款联动回滚。「推广码禁用后停止返佣」开关默认关闭。
 
 ### 5. 部署注意事项