refactor(config,map): 统一抽离卡片背景颜色配置

将多处硬编码的卡片等级背景颜色数组移至公共配置文件，
同时重构英雄列表组件的等级显示逻辑，替换为标签直接赋值。

assets/script/game/map/CardBgComp.ts

@@ -1,14 +1,13 @@
 import { _decorator, Component } from "cc";
+import { CARD_LV_BG_COLORS } from "../common/config/GameSet";
 
 const { ccclass } = _decorator;
 
-const POOL_COLORS = ["green", "blue", "purple", "yellow", "red"];
-
 @ccclass('CardBgComp')
 export class CardBgComp extends Component {
 
-    apply(poolLv: number) {
-        const color = POOL_COLORS[Math.min(poolLv, 5) - 1];
+    apply(card_lv: number) {
+        const color = CARD_LV_BG_COLORS[Math.min(card_lv, 5) - 1];
         this.node.children.forEach(c => c.active = c.name === color);
     }