merge: P8 订阅/recurring + 拒付 chargeback 并入(订阅生命周期/续费/取消/past_due/chargeback/事件集收口)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013nMthbVEmQquxBRKb9Fj8u

# Conflicts:
#	internal/model/testdb.go
#	internal/provider/provider.go
#	internal/router/router.go
#	internal/store/order_query_test.go
#	main.go

internal/handler/metadata_test.go

@@ -30,7 +30,7 @@ func TestV2CreateOrderMetadataWhitelist(t *testing.T) {
 		{AccountID: "fake-a1", Channel: "fake", Region: "global", Enabled: true, Weight: 1},
 	})
 	picker := accounts.NewRouter(areg, nil, nil)
-	g := gateway.New(orders, refunds, preg, picker, oneResolver{}, nopEnqueuer{}, "global")
+	g := gateway.New(orders, refunds, preg, picker, oneResolver{}, nopEnqueuer{}, "global", store.NewSubscriptionStore(db), store.NewChargebackStore(db))
 	r := gin.New()
 	router.SetupV2(r, g)