feat(admin): make all sortable/repeater cards collapsible, collapsed by default

- Add useCollapsibleItems: key-based open state, clickable/keyboard head, aria-expanded
- sortable items with sub-fields and every inline repeater/group row now collapse
- Repeater head summary falls back to the first filled field when no listPreview
- Drop per-schema collapsible/defaultCollapsed for repeater groups (JS + PHP)
- Align FloatBtnItemPanel head with the shared collapse attrs

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

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

@@ -34,17 +34,13 @@ const vipUnitOptions = [
   { label: '月', value: 'month' },
 ];
 
-// 会员商品/续费商品的手风琴配置：默认收起，标题行显示价格与时长摘要。
+// 会员商品/续费商品：标题行显示价格与时长摘要（行默认收起由 AksField 统一处理）。
 const vipProductGroupOptions = {
-  collapsible: true,
-  defaultCollapsed: true,
   listPreview: { prefix: '价格：', titleKey: 'price', descKey: 'time', descUnitKey: 'unit' },
 };
 
-// 积分兑换明细的手风琴配置：默认收起，标题行显示积分与时长摘要。
+// 积分兑换明细：标题行显示积分与时长摘要。
 const vipPointsGroupOptions = {
-  collapsible: true,
-  defaultCollapsed: true,
   listPreview: { prefix: '积分：', titleKey: 'points', descKey: 'time', descUnitKey: 'unit' },
 };