test(pay): 补 settle 并发/跨包全链 e2e/reconcile 装配/alipay 验签健壮性/money 零小数位

- gateway: TestSettleConcurrentSameOrder 真并发钉住 MarkAttemptPaid 行锁不变量
  (文件型 sqlite,规避 in-memory cache=shared 的 SQLITE_LOCKED_SHAREDCACHE)。
- gateway: e2e_fullchain_test.go 补下单→回调→settle→webhook 实际 HTTP 投递→
  delivered 整链(httptest server + 真实 store.WebhookStore/webhook.Notifier)。
- reconcile: main.go 装配抽到 reconcile.Assemble(+Runner.TaskNames 访问器),
  补 assembly_test.go 钉住 7 个后台任务全部注册 + crypto 缺渠道/interval=0 分支。
- alipay: 补验签健壮性(未知多余字段/字段乱序/中文unicode/空值字段),意外定位
  vendor Encoder 对空值字段的真实语义与官方文档描述不同,已记录在测试注释。
- money: 补 TestZeroDecimalCurrencyJPYNotSupported,记录 JPY/KRW 当前未注册进
  exponents(接入会先踩 ErrUnknownCurrency,不是乘除法坑)。

internal/gateway/settle_test.go

@@ -3,8 +3,14 @@ package gateway_test
 import (
 	"context"
 	"encoding/json"
+	"fmt"
+	"sync"
 	"testing"
 
+	"github.com/glebarez/sqlite"
+	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
+
 	"github.com/wangjia/pay/config"
 	"github.com/wangjia/pay/internal/accounts"
 	"github.com/wangjia/pay/internal/gateway"
@@ -12,6 +18,7 @@ import (
 	"github.com/wangjia/pay/internal/provider"
 	"github.com/wangjia/pay/internal/provider/fake"
 	"github.com/wangjia/pay/internal/store"
+	"github.com/wangjia/pay/internal/webhook"
 )
 
 func attemptRef(t *testing.T, orders interface {
@@ -169,6 +176,118 @@ func TestSettleTransientReadErrorIsFailed(t *testing.T) {
 	}
 }
 
+// openFileGatewaySettleDB 开一个 t.TempDir 下的文件型 sqlite(而非 model.OpenTestDB 的
+// in-memory cache=shared)专供并发 Settle 测试:cache=shared 的 in-memory sqlite 下,两个
+// goroutine 各自事务并发写不同表会报 "database table is locked"(SQLITE_LOCKED_SHAREDCACHE,
+// 共享缓存表级锁——不是 busy_timeout 能重试的 SQLITE_BUSY),同 store/refund_test.go
+// openFileGuardedDB 的说明。文件型连接各走独立锁路径,规避此问题;DSN 同样带
+// _txlock=immediate 保留"事务一开始即抢写锁"的守卫语义。
+func openFileGatewaySettleDB(t *testing.T) *gorm.DB {
+	t.Helper()
+	dsn := fmt.Sprintf("file:%s/settle.db?_txlock=immediate&_pragma=busy_timeout(5000)", t.TempDir())
+	db, err := gorm.Open(sqlite.Open(dsn),
+		&gorm.Config{Logger: logger.Default.LogMode(logger.Silent), TranslateError: true})
+	if err != nil {
+		t.Fatalf("open file settle db: %v", err)
+	}
+	if err := db.AutoMigrate(&model.OrderV2{}, &model.Attempt{}, &model.Account{}, &model.Refund{},
+		&model.WebhookDelivery{}, &model.Product{}, &model.ProductPrice{}, &model.OrphanPayment{},
+		&model.Subscription{}, &model.Chargeback{}); err != nil {
+		t.Fatalf("migrate: %v", err)
+	}
+	if err := model.UpgradeWebhookDeliveryIndex(db); err != nil {
+		t.Fatalf("upgrade webhook_deliveries uq_delivery index: %v", err)
+	}
+	sqlDB, _ := db.DB()
+	t.Cleanup(func() { _ = sqlDB.Close() })
+	return db
+}
+
+// TestSettleConcurrentSameOrder 钉住 Settle 依赖的行锁不变量(MarkAttemptPaid 用条件
+// UPDATE ... WHERE status=pending 天然把并发翻转串行化,同 store/refund_test.go
+// TestCreateRefundGuardedConcurrentExactlyOneWins 的真并发模式):两个 goroutine 并发对
+// 同一订单投递同一份成功回调,必须恰好一次真正结算 —— 订单 paid 一次(不重复)、
+// webhook outbox 对该单恰好一行(不双投)、一个 goroutine 得 Settled、另一个得 Duplicate。
+//
+// 用真实 store.WebhookStore + webhook.Notifier(非 spyEnqueuer)驱动:本测试要断言的是
+// "落库的 outbox 行数",spyEnqueuer 的内存 slice/map 本身也不是并发安全的,不适合这里。
+// model.OpenTestDB 的 DSN 已带 _txlock=immediate + busy_timeout,并发事务在读阶段即串行化。
+func TestSettleConcurrentSameOrder(t *testing.T) {
+	db := openFileGatewaySettleDB(t)
+	orders := store.NewOrderStore(db)
+	refunds := store.NewRefundStore(db)
+	subs := store.NewSubscriptionStore(db)
+	chargebacks := store.NewChargebackStore(db)
+	preg := provider.NewRegistry()
+	fp := fake.New()
+	preg.Register(fp)
+	areg := accounts.New([]config.AccountConfig{
+		{AccountID: "fake-a1", Channel: "fake", Region: "global", Enabled: true, Weight: 1},
+	})
+	picker := accounts.NewRouter(areg, nil, nil)
+	ws := store.NewWebhookStore(db)
+	notifier := webhook.NewNotifier(ws,
+		func(string) (config.BizSystemConfig, bool) { return config.BizSystemConfig{}, false },
+		func(string) (bool, error) { return true, nil },
+	)
+	g := gateway.New(orders, refunds, preg, picker, stubResolver{}, notifier, "global", subs, chargebacks)
+
+	ctx := context.Background()
+	res, err := g.CreateOrder(ctx, gateway.CreateOrderInput{SKU: "pro_year", Method: "fake", BizSystem: "pangolin", BizRef: "u-conc"})
+	if err != nil {
+		t.Fatalf("create: %v", err)
+	}
+	ref := attemptRef(t, orders)
+	ev := &provider.PaidEvent{ProviderRef: ref, Status: provider.PaidSucceeded, PaidAmountMinor: 29990000, PaidCurrency: "USDT"}
+
+	var wg sync.WaitGroup
+	results := make([]gateway.SettleResult, 2)
+	errs := make([]error, 2)
+	for i := 0; i < 2; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			results[i], errs[i] = g.Settle(ctx, ev)
+		}(i)
+	}
+	wg.Wait()
+
+	for i, gerr := range errs {
+		if gerr != nil {
+			t.Fatalf("goroutine %d unexpected error: %v", i, gerr)
+		}
+	}
+	processed, duplicate := 0, 0
+	for _, r := range results {
+		switch r {
+		case gateway.SettleProcessed:
+			processed++
+		case gateway.SettleDuplicate:
+			duplicate++
+		default:
+			t.Fatalf("unexpected result %v in %v", r, results)
+		}
+	}
+	if processed != 1 || duplicate != 1 {
+		t.Fatalf("results = %v, want exactly one Processed + one Duplicate", results)
+	}
+
+	o, err := orders.GetOrder(res.OrderNo)
+	if err != nil || o.Status != model.OrderPaidV2 {
+		t.Fatalf("order = %+v, %v, want paid exactly once", o, err)
+	}
+
+	var cnt int64
+	if err := db.Model(&model.WebhookDelivery{}).
+		Where("out_trade_no = ? AND event_type = ?", res.OrderNo, "payment.succeeded").
+		Count(&cnt).Error; err != nil {
+		t.Fatalf("count outbox: %v", err)
+	}
+	if cnt != 1 {
+		t.Fatalf("outbox rows for order = %d, want exactly 1(不双投)", cnt)
+	}
+}
+
 func TestHandleCallbackAndSync(t *testing.T) {
 	g, fp, _, orders := newGateway(t)
 	ctx := context.Background()