fix: 修复内存泄漏和数据库连接泄漏问题

src/main/kotlin/org/mcediagui/DatabaseManager.kt

@@ -5,9 +5,15 @@ import java.io.File
 import java.sql.Connection
 import java.sql.DriverManager
 
+/**
+ * 数据库连接管理器
+ * 使用单一持久连接，避免频繁创建/关闭连接导致文件描述符泄漏
+ */
 object DatabaseManager {
+    @Volatile
     private var connection: Connection? = null
     private lateinit var plugin: JavaPlugin
+    private val lock = Any()
 
     fun init(plugin: JavaPlugin) {
         this.plugin = plugin
@@ -18,16 +24,22 @@ object DatabaseManager {
     }
 
     fun getConnection(): Connection? {
-        if (connection?.isClosed == true) {
-            val dbFile = File(plugin.dataFolder, "mcediagui.db")
-            connection = DriverManager.getConnection("jdbc:sqlite:${dbFile.absolutePath}")
+        synchronized(lock) {
+            val conn = connection
+            if (conn == null || conn.isClosed) {
+                val dbFile = File(plugin.dataFolder, "mcediagui.db")
+                connection = DriverManager.getConnection("jdbc:sqlite:${dbFile.absolutePath}")
+            }
+            return connection
         }
-        return connection
     }
 
     fun close() {
-        try {
-            connection?.close()
-        } catch (_: Exception) {}
+        synchronized(lock) {
+            try {
+                connection?.close()
+                connection = null
+            } catch (_: Exception) {}
+        }
     }
 }

src/main/kotlin/org/mcediagui/McediaGUI.kt

@@ -7,6 +7,8 @@ import org.bukkit.entity.Player
 import org.bukkit.event.EventHandler
 import org.bukkit.event.Listener
 import org.bukkit.event.inventory.InventoryClickEvent
+import org.bukkit.event.inventory.InventoryCloseEvent
+import org.bukkit.event.player.PlayerQuitEvent
 import org.bukkit.inventory.Inventory
 import org.bukkit.inventory.InventoryHolder
 import org.bukkit.inventory.ItemStack
@@ -148,6 +150,21 @@ class McediaGUI(private val plugin: JavaPlugin, private val manager: McediaManag
         }
     }
 
+    @EventHandler
+    fun onInventoryClose(event: InventoryCloseEvent) {
+        val player = event.player as? Player ?: return
+        val state = playerGUIState[player.uniqueId] ?: return
+        // 只有在不等待聊天输入时才清理状态
+        if (state.tempData["awaiting_input"] == null) {
+            playerGUIState.remove(player.uniqueId)
+        }
+    }
+
+    @EventHandler
+    fun onPlayerQuit(event: PlayerQuitEvent) {
+        playerGUIState.remove(event.player.uniqueId)
+    }
+
     fun handleChatInput(player: Player, message: String): Boolean {
         val state = playerGUIState[player.uniqueId] ?: return false
         val awaiting = state.tempData["awaiting_input"] as? String ?: return false

src/main/kotlin/org/mcediagui/McediaListener.kt

@@ -9,6 +9,7 @@ import org.bukkit.event.entity.EntityDamageByEntityEvent
 import org.bukkit.event.player.PlayerArmorStandManipulateEvent
 import org.bukkit.event.player.PlayerInteractAtEntityEvent
 import org.bukkit.event.world.ChunkLoadEvent
+import org.bukkit.event.world.EntitiesUnloadEvent
 import org.bukkit.plugin.java.JavaPlugin
 
 class McediaListener(
@@ -95,4 +96,24 @@ class McediaListener(
         if (!manager.isEnabled()) return
         manager.processPendingOperations(event.chunk.world.name, event.chunk.x, event.chunk.z)
     }
+
+    /**
+     * 当实体被卸载时，检查是否有播放器需要从缓存中保持同步
+     * 注意：这里只处理被实际删除的情况（实体不再存在）
+     */
+    @EventHandler
+    fun onEntitiesUnload(event: EntitiesUnloadEvent) {
+        if (!manager.isEnabled()) return
+        event.entities.filterIsInstance<ArmorStand>().forEach { armorStand ->
+            val customName = armorStand.customName()?.let {
+                net.kyori.adventure.text.serializer.plain.PlainTextComponentSerializer.plainText().serialize(it)
+            } ?: ""
+            if (customName.startsWith(prefix)) {
+                // 如果实体被标记为无效(isDead)，说明是被真正删除了，需要清理缓存
+                if (armorStand.isDead) {
+                    manager.removeFromCache(armorStand.uniqueId)
+                }
+            }
+        }
+    }
 }

src/main/kotlin/org/mcediagui/McediaManager.kt

@@ -203,6 +203,14 @@ class McediaManager(private val plugin: JavaPlugin) {
     }
 
     fun deleteTemplate(playerUUID: UUID, templateId: Int): Boolean = storage?.deleteTemplate(playerUUID, templateId)?.join() ?: false
+
+    /**
+     * 从缓存中移除播放器（用于实体被外部删除时的清理）
+     */
+    fun removeFromCache(uuid: UUID) {
+        players.remove(uuid)
+    }
+
     fun shutdown() { storage?.close(); storage = null; players.clear() }
 }