fix: 添加gradle-wrapper.jar到版本管理，修复gitignore的*.jar误伤

.gitignore

@@ -55,6 +55,9 @@ google-services.json
 *.tar.gz
 *.rar
 
+# Gradle wrapper jar (required for build)
+!gradle/wrapper/gradle-wrapper.jar
+
 # virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
 hs_err_pid*
 replay_pid*

app/src/main/java/com/unogame/MainActivity.kt

@@ -409,9 +409,7 @@ fun UnoApp() {
                 botNames = botNames,
                 handOffset = handOffset,
                 onBackToMenu = {
-                    navController.navigate(Screen.MainMenu.route) {
-                        popUpTo(0) { inclusive = true }
-                    }
+                    navController.popBackStack()
                 }
             )
         }

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

@@ -113,9 +113,9 @@ fun GameOverScreen(
                     contentColor = Color.Black
                 )
             ) {
-                Icon(Icons.Default.Home, null)
+                Icon(Icons.Default.Refresh, null)
                 Spacer(modifier = Modifier.width(8.dp))
-                Text("返回主菜单", fontSize = 18.sp, fontWeight = FontWeight.Bold)
+                Text("再来一局", fontSize = 18.sp, fontWeight = FontWeight.Bold)
             }
         }
     }

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

@@ -36,6 +36,7 @@ fun GameScreen(
     onChallengeUno: (String) -> Unit = {},
     onShowLog: () -> Unit = {},
     onPlaySeven: (Int) -> Unit = {},
+    onBack: () -> Unit = {},
     isSevenZeroMode: Boolean = false,
     handOffset: Float = 0f,
     errorMessage: String
@@ -128,6 +129,9 @@ fun GameScreen(
                     color = LocalTextOnTable.current.copy(alpha = 0.6f),
                     fontSize = 14.sp
                 )
+                IconButton(onClick = { onBack() }, modifier = Modifier.size(28.dp)) {
+                    Icon(Icons.Default.Close, "退出", tint = LocalTextOnTable.current.copy(alpha = 0.5f), modifier = Modifier.size(18.dp))
+                }
             }
 
             Spacer(modifier = Modifier.height(8.dp))

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

@@ -1,6 +1,7 @@
 package com.unogame.ui.screens
 
 import android.content.Context
+import androidx.activity.compose.BackHandler
 import androidx.compose.animation.core.animateFloatAsState
 import androidx.compose.animation.core.spring
 import androidx.compose.foundation.background
@@ -170,6 +171,7 @@ fun LocalGameScreen(
     var showLogDialog by remember { mutableStateOf(false) }
     var showSwapTargetPicker by remember { mutableStateOf(false) }
     var pendingSwapState by remember { mutableStateOf<GameState?>(null) }
+    var showExitConfirm by remember { mutableStateOf(false) }
 
     val myPlayerId = "human"
     val currentPlayer = gameState.currentPlayer
@@ -611,6 +613,27 @@ fun LocalGameScreen(
             playerCount = totalPlayers
         )
     } else {
+        // 退出确认弹窗
+        if (showExitConfirm) {
+            AlertDialog(
+                onDismissRequest = { showExitConfirm = false },
+                title = { Text("退出游戏", color = GoldAccent) },
+                text = { Text("确定要退出当前对局吗？", color = Color.White.copy(alpha = 0.8f)) },
+                confirmButton = {
+                    TextButton(onClick = { showExitConfirm = false; onBackToMenu() }) {
+                        Text("退出", color = UnoRed)
+                    }
+                },
+                dismissButton = {
+                    TextButton(onClick = { showExitConfirm = false }) {
+                        Text("继续", color = GoldAccent)
+                    }
+                },
+                containerColor = DarkSurface
+            )
+        }
+        // 拦截系统返回键
+        BackHandler { showExitConfirm = true }
         GameScreen(
             gameState = gameState,
             myCards = displayCards,
@@ -624,6 +647,7 @@ fun LocalGameScreen(
             onDrawCard = { executeDraw() },
             onChooseColor = { selectedWildColor = it },
             onShowLog = { showLogDialog = true },
+            onBack = { showExitConfirm = true },
             onCallUno = {
                 // Mark player as having called UNO
                 val updated = gameState.players.map {