feat(v2): 一次性收款管线 CreateOrder/GetOrder/Retry/Cancel + DBProductResolver

internal/provider/fake/fake.go

@@ -1,12 +1,16 @@
 // Package fake is an in-process Provider used to exercise the pay v2 pipeline
 // end-to-end without any real channel. Real adapters (crypto/alipay/stripe) land
-// in P3. Deterministic: provider_ref = "FAKE-"+OutTradeNo; render_type = crypto_address.
+// in P3. provider_ref = "FAKE-"+OutTradeNo+"-"+<nanosecond>; render_type = crypto_address.
+// The nanosecond suffix is fake-only: Attempt has uniqueIndex(channel,provider_ref),
+// and a retry on the same order/method would otherwise reuse the same OutTradeNo and
+// collide. Real channels naturally mint a distinct ref per create call.
 package fake
 
 import (
 	"context"
 	"encoding/json"
 	"errors"
+	"strconv"
 	"sync"
 	"time"
 
@@ -33,8 +37,9 @@ func (p *Provider) Capabilities() provider.Capabilities {
 
 func (p *Provider) Create(_ context.Context, req provider.CreateRequest) (*provider.Session, error) {
 	exp := time.Now().Add(15 * time.Minute)
+	ref := "FAKE-" + req.OutTradeNo + "-" + strconv.FormatInt(time.Now().UnixNano(), 36)
 	return &provider.Session{
-		ProviderRef: "FAKE-" + req.OutTradeNo,
+		ProviderRef: ref,
 		RenderType:  provider.RenderCryptoAddress,
 		Payload: map[string]any{
 			"address":      "TFake" + req.Account.AccountID + req.OutTradeNo,