fix(vip): align modal copy fields with reference theme backend

Rename and reposition the two VIP modal copy settings to match the zibll reference backend, drop dead renew/upgrade desc config, and align copy defaults.

- pay_user_vip_desc: modal top intro -> 会员介绍, textarea -> input (one-line), zibll help text, default copy from zibll

- pay_user_vip_more: bottom note -> 开通会员更多内容, rows 4 + sanitize_type html (HTML was stripped on save), zibll help text and three-div default

- Both fields move from the member-level group to a new 界面文案 (modal-copy) group at the end of the VIP section; dependsOn any-of-two-levels adapted from zibll's pay_user_vip_1_s dependency

- Copy defaults synced in three places (SPA schema, PHP schema, PaymentRuntime fallbacks, since Settings::get_all() does not merge schema defaults): 黄金会员/钻石会员, 尊享专属特权, zibll four-item equity list

- Remove vip_renew_desc / vip_upgrade_desc: AKSRT has no renew/upgrade card render surface (render_vip_card takes no type) and zero consumers repo-wide; zibll renders them on page-level cards only

- pay_user_vip_1/2_equity and pay_vip_pass_charge_desc gain sanitize_type html so admins no longer lose list/HTML markup on save

Verification: new tests/widget-system/vip-modal-copy-fields.test.cjs (6 contract tests); node --test tests/**/*.test.cjs 634/634 pass; php -l clean on both changed PHP files; assets/admin npm run build succeeds

assets/admin/src/schema/sections/payment/recharge.js

@@ -111,7 +111,7 @@ export const rechargeSchema = {
         { key: 'points_pass_exchange_desc', label: '卡密兑换积分说明', type: 'textarea', default: '', rows: 2, dependsOn: { key: 'points_pass_exchange_s', value: true }, help: '用户使用卡密兑换积分时显示的内容，建议为提醒事项、兑换协议等，支持HTML代码' },
         { key: 'points_pass_exchange_only_password', label: '积分卡密单密码模式', type: 'switch', default: false, dependsOn: { key: 'points_pass_exchange_s', value: true }, help: '积分卡密仅需输入密码，不需要卡号' },
         { key: 'pay_vip_pass_charge_s', label: '启用卡密兑换会员功能', type: 'switch', default: false, help: '开启后用户可在会员购买/续费弹窗选择「卡密」渠道，使用会员卡密直接兑换会员' },
-        { key: 'pay_vip_pass_charge_desc', label: '卡密兑换会员说明', type: 'textarea', default: '', rows: 2, dependsOn: { key: 'pay_vip_pass_charge_s', value: true }, help: '用户使用卡密兑换会员时显示的内容，建议为提醒事项、兑换协议等，支持HTML代码' },
+        { key: 'pay_vip_pass_charge_desc', label: '卡密兑换会员说明', type: 'textarea', sanitize_type: 'html', default: '', rows: 2, dependsOn: { key: 'pay_vip_pass_charge_s', value: true }, help: '用户使用卡密兑换会员时显示的内容，建议为提醒事项、兑换协议等，支持HTML代码' },
         { key: 'pay_vip_pass_charge_only_password', label: '会员卡密单密码模式', type: 'switch', default: false, dependsOn: { key: 'pay_vip_pass_charge_s', value: true }, help: '会员卡密仅需输入密码，不需要卡号；默认关闭，会员卡需输入卡号和密码（与其他卡密兑换一致）' },
       ],
     },