refactor: 移除内存面板并添加显示控制标志

在 MissionComp 的 onLoad 方法中初始化 showMemoryPanel 为 false，并调用 removeMemoryPanel 来销毁内存面板节点。
同时，将 update 方法中对 updateMemoryPanel 的调用移除，以停止面板的持续更新。

assets/script/game/map/MissionComp.ts

@@ -77,12 +77,13 @@ export class MissionComp extends CCComp {
     // 记录已触发的特殊刷怪索引
 
     onLoad(){
+        this.showMemoryPanel = false
         this.on(GameEvent.MissionStart,this.mission_start,this)
         // this.on(GameEvent.HeroDead,this.do_hero_dead,this)
         // this.on(GameEvent.FightEnd,this.fight_end,this)
         this.on(GameEvent.MissionEnd,this.mission_end,this)
         this.on(GameEvent.DO_AD_BACK,this.do_ad,this)
-        this.initMemoryPanel()
+        this.removeMemoryPanel()
     }
     protected update(dt: number): void {
         if(!smc.mission.play) return
@@ -94,7 +95,6 @@ export class MissionComp extends CCComp {
             this.FightTime-=dt
             // 检查特殊刷怪时间
             this.update_time();
-            this.updateMemoryPanel(dt);
         }
     }
     update_time(){
@@ -331,6 +331,15 @@ export class MissionComp extends CCComp {
         this.memoryLabel = label;
     }
 
+    private removeMemoryPanel() {
+        const panel = this.time_node?.getChildByName("mem_panel");
+        if (panel) {
+            panel.destroy();
+        }
+        this.memoryLabel = null;
+        this.lastMemoryText = "";
+    }
+
 
     private updateMemoryPanel(dt: number) {
         if (!this.showMemoryPanel || !this.memoryLabel) return;