fix: ignore ami and user_data changes to prevent EC2 replacement

infra/terraform/ec2.tf

@@ -98,4 +98,8 @@ resource "aws_instance" "app" {
     Project     = var.project_name
     Environment = var.environment
   }
-}
+
+  lifecycle {
+    ignore_changes = [ami, user_data]
+  }
+}