refactor: 将多个 fmt.Println 日志替换为 log.Printf，以统一日志输出格式并提升可读性

handler/steamplaying/steam_playing.go

@@ -196,17 +196,17 @@ func RoundCheckSteamPlaying() {
 
 		allSteamIDs, err := getAllSteamID()
 		if err != nil {
-			fmt.Println("获取所有steamID失败: ", err)
+			log.Printf("获取所有steamID失败: %v\n", err)
 			return
 		}
 		groups, err := getAllGroupID()
 		if err != nil {
-			fmt.Println("获取群列表失败: ", err)
+			log.Printf("获取群列表失败: %v\n", err)
 			return
 		}
 		gamePlayingMap, players, err := checkDiffSteamGameStatus(allSteamIDs, playingMap)
 		if err != nil {
-			fmt.Println("获取游戏列表失败: ", err)
+			log.Printf("获取游戏列表失败: %v\n", err)
 			return
 		}