fix: 包年 CNY / 永久 USD 分币种结账

按档位分别拼 Waffo currency，避免永久商品用 CNY 报不可用。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/internal/service/payment/waffo_test.go

@@ -6,12 +6,14 @@ import (
 	"testing"
 )
 
-func TestBuildCheckoutURL_YearlyOnetime(t *testing.T) {
+func TestBuildCheckoutURL_YearlyOnetimeCNY(t *testing.T) {
 	cfg := WaffoConfig{
 		StoreSlug:          "opsxshell-pwsi6m4n",
 		ProductIDYearly:    "PROD_1BIezCi932IbgCzRIV8hcJ",
 		ProductIDPerpetual: "PROD_0pcnzzT4nalEkkcdyIUoD5",
 		Currency:           "CNY",
+		CurrencyYearly:     "CNY",
+		CurrencyPerpetual:  "USD",
 		Environment:        "test",
 		SuccessURL:         "opsxshell://pro/activated",
 	}
@@ -31,19 +33,18 @@ func TestBuildCheckoutURL_YearlyOnetime(t *testing.T) {
 		t.Fatalf("type=%s want onetime", q.Get("type"))
 	}
 	if q.Get("currency") != "CNY" {
-		t.Fatalf("currency=%s", q.Get("currency"))
-	}
-	if q.Get("test") != "true" {
-		t.Fatalf("test=%s", q.Get("test"))
+		t.Fatalf("currency=%s want CNY", q.Get("currency"))
 	}
 }
 
-func TestBuildCheckoutURL_PerpetualOnetime(t *testing.T) {
+func TestBuildCheckoutURL_PerpetualOnetimeUSD(t *testing.T) {
 	cfg := WaffoConfig{
 		StoreSlug:          "opsxshell-pwsi6m4n",
 		ProductIDYearly:    "PROD_1BIezCi932IbgCzRIV8hcJ",
 		ProductIDPerpetual: "PROD_0pcnzzT4nalEkkcdyIUoD5",
 		Currency:           "CNY",
+		CurrencyYearly:     "CNY",
+		CurrencyPerpetual:  "USD",
 		Environment:        "test",
 		SuccessURL:         "opsxshell://pro/activated",
 	}
@@ -58,7 +59,11 @@ func TestBuildCheckoutURL_PerpetualOnetime(t *testing.T) {
 	if !strings.Contains(u.Path, "PROD_0pcnzzT4nalEkkcdyIUoD5") {
 		t.Fatalf("perpetual product missing: %s", raw)
 	}
-	if u.Query().Get("type") != "onetime" {
-		t.Fatalf("type=%s want onetime", u.Query().Get("type"))
+	q := u.Query()
+	if q.Get("type") != "onetime" {
+		t.Fatalf("type=%s want onetime", q.Get("type"))
+	}
+	if q.Get("currency") != "USD" {
+		t.Fatalf("currency=%s want USD", q.Get("currency"))
 	}
 }