fix(mission): 修复组件生命周期与节点安全访问问题

- 移除 MissionCardComp.onLoad 中自动触发的 onMissionStart，改为由 MissionComp 通过 scheduleOnce 事件驱动，确保组件初始化顺序
- 在设置节点 active 属性前增加节点有效性检查，避免节点已销毁时访问导致的错误
- 在更新计时器 UI 时增加节点和组件存在性检查，防止空引用异常

assets/script/game/map/MissionCardComp.ts

@@ -167,7 +167,7 @@ export class MissionCardComp extends CCComp {
         this.cacheCardComps();
         this.layoutCardSlots();
         this.initCardsPanelPos();
-        this.onMissionStart();
+        // this.onMissionStart(); // 移除 onLoad 自动触发，改为事件驱动
         mLogger.log(this.debugMode, "MissionCardComp", "onLoad init", {
             slots: this.cardComps.length,
             poolLv: this.poolLv
@@ -231,7 +231,9 @@ export class MissionCardComp extends CCComp {
         // this.resetButtonScale(this.cards_up);
         this.updateCoinAndCostUI();
         this.updateHeroNumUI(false, false);
-        this.node.active = true;
+        if (this.node && this.node.isValid) {
+            this.node.active = true;
+        }
         const cards = this.buildDrawCards();
         this.dispatchCardsToSlots(cards);
         mLogger.log(this.debugMode, "MissionCardComp", "mission start", {
@@ -243,7 +245,9 @@ export class MissionCardComp extends CCComp {
     onMissionEnd() {
         this.clearAllCards();
         this.clearHeroInfoPanels();
-        this.node.active = false;
+        if (this.node && this.node.isValid) {
+            this.node.active = false;
+        }
     }
 
     start() {
@@ -264,7 +268,9 @@ export class MissionCardComp extends CCComp {
 
     /** 关闭面板（不销毁数据模型，仅隐藏） */
     close() {
-      this.node.active = false;
+        if (this.node && this.node.isValid) {
+            this.node.active = false;
+        }
     }
 
     // ======================== 事件绑定 ========================

assets/script/game/map/MissionComp.ts

@@ -189,9 +189,12 @@ export class MissionComp extends CCComp {
     }
 
     onAdded(args: any) {
-        // UI加载完成后，抛出MissionStart事件，启动战斗（触发自身 mission_start 及其他系统）
+        // 使用 scheduleOnce 将事件推迟到下一帧执行，
-        oops.message.dispatchEvent(GameEvent.MissionStart, {});
+        // 确保所有关联组件（如 MissionCardComp 等）都已经完成其 onLoad 生命周期。
-        this.mission_start();
+        this.scheduleOnce(() => {
+            oops.message.dispatchEvent(GameEvent.MissionStart, {});
+            this.mission_start();
+        }, 0);
     }
 
     onDestroy(){
@@ -244,7 +247,13 @@ export class MissionComp extends CCComp {
         if (this.isBossWave) {
             const str = "∞";
             if (str != this.lastTimeStr) {
-                this.time_node.getChildByName("time").getComponent(Label).string = str;
+                if (this.time_node && this.time_node.isValid) {
+                    const timeChild = this.time_node.getChildByName("time");
+                    if (timeChild) {
+                        const label = timeChild.getComponent(Label);
+                        if (label) label.string = str;
+                    }
+                }
                 this.lastTimeStr = str;
                 this.lastTimeSecond = -1;
             }
@@ -260,7 +269,13 @@ export class MissionComp extends CCComp {
         const wave = Math.max(1, this.currentWave || smc.vmdata.mission_data.level || 1);
         let str = `${m.toString().padStart(2, '0')}:${s.toString().padStart(2, '0')}`;
         if(str != this.lastTimeStr){
-            this.time_node.getChildByName("time").getComponent(Label).string = str;
+            if (this.time_node && this.time_node.isValid) {
+                const timeChild = this.time_node.getChildByName("time");
+                if (timeChild) {
+                    const label = timeChild.getComponent(Label);
+                    if (label) label.string = str;
+                }
+            }
             this.lastTimeStr = str;
         }
     }