fix bug and better return value on existing games

backend/src/main.rs

@@ -78,14 +78,14 @@ async fn add_game(
     let mut games = game_list.lock().await;
     let mut game = game.into_inner();
 
-    if games.iter().any(|g| {
+    game.title = game.title.trim().to_string();
+
+    if let Some(existing) = games.iter().find(|g| {
         g.title == game.title || (g.remote_id == game.remote_id && g.source == game.source)
     }) {
-        return None;
+        return Some(existing.clone());
     }
 
-    game.title = game.title.trim().to_string();
-
     games.push(game.clone());
 
     games.sort_unstable_by(|g1, g2| g1.title.cmp(&g2.title));