feat(payment): add complete payment system with multi-provider support

Add a full payment and subscription system supporting EasyPay (Alipay/WeChat),
Stripe, and direct Alipay/WeChat Pay providers with multi-instance load balancing.

backend/internal/service/wire.go

@@ -5,7 +5,9 @@ import (
 	"database/sql"
 	"time"
 
+	dbent "github.com/Wei-Shaw/sub2api/ent"
 	"github.com/Wei-Shaw/sub2api/internal/config"
+	"github.com/Wei-Shaw/sub2api/internal/payment"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/logger"
 	"github.com/google/wire"
 	"github.com/redis/go-redis/v9"
@@ -460,4 +462,20 @@ var ProviderSet = wire.NewSet(
 	NewGroupCapacityService,
 	NewChannelService,
 	NewModelPricingResolver,
+	ProvidePaymentConfigService,
+	NewPaymentService,
+	ProvidePaymentOrderExpiryService,
 )
+
+// ProvidePaymentConfigService wraps NewPaymentConfigService to accept the named
+// payment.EncryptionKey type instead of raw []byte, avoiding Wire ambiguity.
+func ProvidePaymentConfigService(entClient *dbent.Client, settingRepo SettingRepository, key payment.EncryptionKey) *PaymentConfigService {
+	return NewPaymentConfigService(entClient, settingRepo, []byte(key))
+}
+
+// ProvidePaymentOrderExpiryService creates and starts PaymentOrderExpiryService.
+func ProvidePaymentOrderExpiryService(paymentSvc *PaymentService) *PaymentOrderExpiryService {
+	svc := NewPaymentOrderExpiryService(paymentSvc, 60*time.Second)
+	svc.Start()
+	return svc
+}