feat(hero): 新增英雄按等级切换不同颜色描边的功能

新增紫色描边shader与对应材质资源，为英雄预制体注册四种颜色描边材质
重构FlashSprite组件支持按等级切换描边，在英雄初始化与升级时自动更新描边样式

assets/script/game/hero/hit-flash-white/scripts/FlashSprite.ts

@@ -5,24 +5,73 @@ const { ccclass, property } = _decorator;
 export class FlashSprite extends Component {
 
     @property(Material) 
-    hitFlashMaterial: Material;
-    orginalFlashMaterial: Material;
-    sprite: Sprite;
+    hitFlashMaterial: Material | null = null;
+
+    @property({ type: Material, tooltip: '绿色描边材质(2级)' })
+    outlineMatGreen: Material | null = null;
+
+    @property({ type: Material, tooltip: '蓝色描边材质(3级)' })
+    outlineMatBlue: Material | null = null;
+
+    @property({ type: Material, tooltip: '紫色描边材质(4级)' })
+    outlineMatPurple: Material | null = null;
+
+    @property({ type: Material, tooltip: '黄色描边材质(5级)' })
+    outlineMatYellow: Material | null = null;
+
+    orginalFlashMaterial: Material | null = null;
+    defaultMaterial: Material | null = null; // 缓存最原始的无描边材质
+    sprite: Sprite | null = null;
 
     start() {
         this.sprite = this.node.getComponent(Sprite);
-        this.orginalFlashMaterial = this.sprite.getRenderMaterial(0);   
-
+        // 记录最初的默认材质（无描边）
+        if (this.sprite) {
+            this.defaultMaterial = this.sprite.getRenderMaterial(0);
+            if (!this.orginalFlashMaterial) {
+                this.orginalFlashMaterial = this.defaultMaterial;
+            }
+        }
     }
 
-    update(deltaTime: number) {
-        
+    /**
+     * 根据英雄等级设置描边材质
+     * @param level 英雄等级 (1=无描边, 2=绿, 3=蓝, 4=紫, 5=黄)
+     */
+    public setOutlineByLevel(level: number) {
+        if (!this.sprite) {
+            this.sprite = this.node.getComponent(Sprite);
+        }
+
+        let targetMat: Material | null = null;
+        if (level === 2) {
+            targetMat = this.outlineMatGreen;
+        } else if (level === 3) {
+            targetMat = this.outlineMatBlue;
+        } else if (level === 4) {
+            targetMat = this.outlineMatPurple;
+        } else if (level >= 5) {
+            targetMat = this.outlineMatYellow;
+        } else {
+            // 1级或异常情况，使用最原始的无描边材质
+            targetMat = this.defaultMaterial;
+        }
+
+        if (targetMat && this.sprite) {
+            // 更新基础材质，确保闪白结束后恢复到这个描边材质
+            this.orginalFlashMaterial = targetMat;
+            this.sprite.setSharedMaterial(targetMat, 0);
+        }
     }
 
     public clickFlash() {
+        if (!this.sprite || !this.hitFlashMaterial) return;
+        
         this.sprite.setSharedMaterial(this.hitFlashMaterial, 0);
         this.scheduleOnce(() => {
-            this.sprite.setSharedMaterial(this.orginalFlashMaterial, 0);
+            if (this.sprite && this.orginalFlashMaterial) {
+                this.sprite.setSharedMaterial(this.orginalFlashMaterial, 0);
+            }
         }, 0.1);
     }
 }