refactor(payment): 支付插件 - 宿主仅通过 RPC 包加载并保护订单版本

backend/internal/repository/payment.go

@@ -154,6 +154,25 @@ func (r *Repository) PaymentOrderCountForProvider(providerID string) (int64, err
 	return count, err
 }
 
+// ActivePaymentOrderCountForPlugin reports orders that still need the plugin
+// runtime for create retries, callbacks, queries or close operations.
+func (r *Repository) ActivePaymentOrderCountForPlugin(pluginID, pluginVersion string) (int64, error) {
+	query := r.db.Model(&model.PaymentOrder{}).Where("plugin_id = ? AND status IN ?", strings.TrimSpace(pluginID), []model.PaymentOrderStatus{
+		model.PaymentOrderCreated, model.PaymentOrderPending, model.PaymentOrderClosing, model.PaymentOrderCreateFailed,
+	})
+	if strings.TrimSpace(pluginVersion) != "" {
+		// Rows created before plugin version pinning have an empty version. Keep
+		// them protected during upgrades because they still depend on this
+		// plugin's historical runtime.
+		query = query.Where("(plugin_version = ? OR plugin_version = '' OR plugin_version IS NULL)", strings.TrimSpace(pluginVersion))
+	}
+	var count int64
+	if err := query.Count(&count).Error; err != nil {
+		return 0, err
+	}
+	return count, nil
+}
+
 func (r *Repository) SaveVerifiedPaymentNotification(notification *model.PaymentNotification) (bool, error) {
 	created := r.db.Clauses(clause.OnConflict{
 		Columns: []clause.Column{{Name: "provider_id"}, {Name: "provider_event_id"}}, DoNothing: true,

backend/internal/repository/payment_test.go

@@ -59,6 +59,29 @@ func TestCompletePaymentOrderGrantsCreditsExactlyOnce(t *testing.T) {
 	}
 }
 
+func TestActivePaymentOrderCountForPluginScopesVersionAndState(t *testing.T) {
+	db := openPaymentTestDB(t)
+	repo := New(db)
+	orders := []model.PaymentOrder{
+		{ID: "plugin-v1-pending", UserID: "u1", IdempotencyKey: "i1", MerchantOrderNo: "m1", ProviderID: "p1", PluginID: "plugin", PluginVersion: "1.0.0", Status: model.PaymentOrderPending},
+		{ID: "plugin-legacy-pending", UserID: "u5", IdempotencyKey: "i5", MerchantOrderNo: "m5", ProviderID: "p1", PluginID: "plugin", Status: model.PaymentOrderPending},
+		{ID: "plugin-v1-credited", UserID: "u2", IdempotencyKey: "i2", MerchantOrderNo: "m2", ProviderID: "p1", PluginID: "plugin", PluginVersion: "1.0.0", Status: model.PaymentOrderCredited},
+		{ID: "plugin-v2-pending", UserID: "u3", IdempotencyKey: "i3", MerchantOrderNo: "m3", ProviderID: "p1", PluginID: "plugin", PluginVersion: "2.0.0", Status: model.PaymentOrderPending},
+		{ID: "other-pending", UserID: "u4", IdempotencyKey: "i4", MerchantOrderNo: "m4", ProviderID: "p2", PluginID: "other", PluginVersion: "1.0.0", Status: model.PaymentOrderPending},
+	}
+	if err := db.Create(&orders).Error; err != nil {
+		t.Fatal(err)
+	}
+	count, err := repo.ActivePaymentOrderCountForPlugin("plugin", "1.0.0")
+	if err != nil || count != 2 {
+		t.Fatalf("version-scoped active count = %d, error = %v", count, err)
+	}
+	count, err = repo.ActivePaymentOrderCountForPlugin("plugin", "")
+	if err != nil || count != 3 {
+		t.Fatalf("all-version active count = %d, error = %v", count, err)
+	}
+}
+
 func TestCompletePaymentOrderRejectsAmountMismatchWithoutGrant(t *testing.T) {
 	db := openPaymentTestDB(t)
 	repo := New(db)