fix: 修复积分榜旧数据scoreDetail为null导致点击闪退的NPE

app/src/main/java/com/unogame/ui/screens/LocalGameScreen.kt

@@ -39,7 +39,7 @@ data class ScoreEntry(
     val playerCount: Int,
     val turnNumber: Int,
     val date: Long,
-    val scoreDetail: String = ""
+    val scoreDetail: String? = ""
 )
 
 object Scoreboard {

app/src/main/java/com/unogame/ui/screens/ScoreboardScreen.kt

@@ -233,7 +233,7 @@ fun ScoreboardScreen(onBack: () -> Unit) {
     // Detail dialog
     if (showDetailDialog && detailEntry != null) {
         val entry = detailEntry!!
-        val grouped = entry.scoreDetail.split(", ").filter { it.isNotEmpty() }
+        val grouped = (entry.scoreDetail ?: "").split(", ").filter { it.isNotEmpty() }
             .groupBy { it }
             .mapValues { it.value.size }
         AlertDialog(