add more validation

backend/src/main.rs

@@ -83,6 +83,10 @@ async fn add_game(
 
     game.title = game.title.trim().to_string();
 
+    if game.remote_id == 0 {
+        return None;
+    }
+
     if let Some(existing) = games.iter().find(|g| {
         g.title == game.title || (g.remote_id == game.remote_id && g.source == game.source)
     }) {