refactor: add save()/savePlayer() methods on game instances

Wrap free persistence functions in instance methods for cleaner call
sites (gi.save() instead of saveGame(gi.queries, gi.game)). Methods
log errors via zerolog before returning them.

snake/store.go

@@ -62,7 +62,7 @@ func (ss *SnakeStore) Create(width, height int, mode GameMode, speed int) *Snake
 	ss.gamesMu.Unlock()
 
 	if ss.queries != nil {
-		saveSnakeGame(ss.queries, sg) //nolint:errcheck
+		si.save() //nolint:errcheck
 	}
 
 	return si
@@ -206,8 +206,8 @@ func (si *SnakeGameInstance) Join(player *Player) bool {
 	si.game.Players[slot] = player
 
 	if si.queries != nil {
-		saveSnakePlayer(si.queries, si.game.ID, player) //nolint:errcheck
-		saveSnakeGame(si.queries, si.game)              //nolint:errcheck
+		si.savePlayer(player) //nolint:errcheck
+		si.save()             //nolint:errcheck
 	}
 
 	si.notify()
@@ -293,7 +293,7 @@ func (si *SnakeGameInstance) CreateRematch() *SnakeGameInstance {
 	si.game.RematchGameID = &newID
 
 	if si.queries != nil {
-		saveSnakeGame(si.queries, si.game) //nolint:errcheck
+		si.save() //nolint:errcheck
 	}
 	si.gameMu.Unlock()