Organize backend into product executable and shared Go modules

backend/shared/database/transaction/context.go

@@ -0,0 +1,12 @@
+package transaction
+
+import (
+	"context"
+
+	"go.mongodb.org/mongo-driver/v2/mongo"
+)
+
+func ActiveMongoTransaction(ctx context.Context) bool {
+	session := mongo.SessionFromContext(ctx)
+	return session != nil && session.TransactionRunning()
+}