feat(server/pay): 订单列表端点 + 分币种展示价 + 富字段详情

- GET /v1/pay/orders 订单列表(Store.ListByUser,本地台账倒序)
- catalog 增 PriceUsdtMicro(USDT 一口价展示) + SettlementCurrency/DisplayAmountMinor
- 下单按支付方式落展示金额/结算币种(crypto→USDT / 法币→CNY),webhook 覆盖实际
- GetOrder 详情回带 sku/plan/method/amount/currency/created_at/paid_at
- 新增 List 越权/倒序/富字段 + 分币种展示金额 + 详情富字段测试
- 修 3 个 pre-existing 迁移测试(renumber 后 21→23 遗留)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013nMthbVEmQquxBRKb9Fj8u

server/cmd/server/main.go

@@ -452,6 +452,7 @@ func mountV1(r chi.Router, sqlDB *sql.DB, rdb *redis.Client, nodeSvc *nodes.Serv
 				protected.Get("/notices", accountAPI.ListNotices)
 				if payHandler != nil {
 					protected.Get("/pay/catalog", payHandler.Catalog)
+					protected.Get("/pay/orders", payHandler.List)
 					protected.Post("/pay/orders", payHandler.CreateOrder)
 					protected.Get("/pay/orders/{orderNo}", payHandler.GetOrder)
 					protected.Post("/pay/orders/{orderNo}/retry", payHandler.Retry)