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/internal/pay/store.go

@@ -23,6 +23,7 @@ type PurchaseRow struct {
 	Channel     string
 	SubID       sql.NullInt64
 	PaidAt      sql.NullTime
+	CreatedAt   time.Time
 }
 
 type Store struct {
@@ -38,13 +39,15 @@ func (s *Store) BeginTx(ctx context.Context) (*sql.Tx, error) {
 	return s.db.BeginTx(ctx, &sql.TxOptions{Isolation: sql.LevelReadCommitted})
 }
 
-// Insert 下单成功后落台账(status=created)。
-func (s *Store) Insert(ctx context.Context, userID int64, bizRef, sku, outTradeNo, method string) error {
+// Insert 下单成功后落台账(status=created)。amountMinor/currency 是下单时的
+// **展示预估**(按支付方式的结算币种,见 DisplayAmountMinor),webhook 到账后由
+// MarkPaidTx 用实际结算金额覆盖——保证订单列表/详情在支付前也有金额可显。
+func (s *Store) Insert(ctx context.Context, userID int64, bizRef, sku, outTradeNo, method string, amountMinor int64, currency string) error {
 	now := time.Now().UTC()
 	_, err := s.db.ExecContext(ctx,
-		`INSERT INTO pay_purchases (user_id, biz_ref, sku, out_trade_no, method, status, created_at, updated_at)
-		 VALUES (?, ?, ?, ?, ?, 'created', ?, ?)`,
-		userID, bizRef, sku, outTradeNo, method, now, now)
+		`INSERT INTO pay_purchases (user_id, biz_ref, sku, out_trade_no, method, status, amount_minor, currency, created_at, updated_at)
+		 VALUES (?, ?, ?, ?, ?, 'created', ?, ?, ?, ?)`,
+		userID, bizRef, sku, outTradeNo, method, amountMinor, currency, now, now)
 	if err != nil {
 		return fmt.Errorf("pay.Store.Insert: %w", err)
 	}
@@ -52,17 +55,42 @@ func (s *Store) Insert(ctx context.Context, userID int64, bizRef, sku, outTradeN
 }
 
 const purchaseCols = `id, user_id, biz_ref, sku, out_trade_no, method, status,
-	amount_minor, currency, channel, sub_id, paid_at`
+	amount_minor, currency, channel, sub_id, paid_at, created_at`
 
 func scanPurchase(row *sql.Row) (*PurchaseRow, error) {
 	var p PurchaseRow
 	if err := row.Scan(&p.ID, &p.UserID, &p.BizRef, &p.SKU, &p.OutTradeNo, &p.Method,
-		&p.Status, &p.AmountMinor, &p.Currency, &p.Channel, &p.SubID, &p.PaidAt); err != nil {
+		&p.Status, &p.AmountMinor, &p.Currency, &p.Channel, &p.SubID, &p.PaidAt, &p.CreatedAt); err != nil {
 		return nil, err
 	}
 	return &p, nil
 }
 
+// ListByUser 按用户列历史订单(created_at 倒序,复用 idx_pay_user 索引)。
+// 供「订单列表」页;limit 上限保护。
+func (s *Store) ListByUser(ctx context.Context, userID int64, limit int) ([]PurchaseRow, error) {
+	if limit <= 0 || limit > 200 {
+		limit = 100
+	}
+	rows, err := s.db.QueryContext(ctx,
+		`SELECT `+purchaseCols+` FROM pay_purchases WHERE user_id = ? ORDER BY created_at DESC, id DESC LIMIT ?`,
+		userID, limit)
+	if err != nil {
+		return nil, fmt.Errorf("pay.Store.ListByUser: %w", err)
+	}
+	defer rows.Close()
+	var out []PurchaseRow
+	for rows.Next() {
+		var p PurchaseRow
+		if err := rows.Scan(&p.ID, &p.UserID, &p.BizRef, &p.SKU, &p.OutTradeNo, &p.Method,
+			&p.Status, &p.AmountMinor, &p.Currency, &p.Channel, &p.SubID, &p.PaidAt, &p.CreatedAt); err != nil {
+			return nil, fmt.Errorf("pay.Store.ListByUser scan: %w", err)
+		}
+		out = append(out, p)
+	}
+	return out, rows.Err()
+}
+
 // GetForUser 按 (userID, outTradeNo) 取行——所有权校验由查询本身完成。
 func (s *Store) GetForUser(ctx context.Context, userID int64, outTradeNo string) (*PurchaseRow, error) {
 	return scanPurchase(s.db.QueryRowContext(ctx,