refactor(map): 移除所有卡牌购买的扣费逻辑，改为免费获取

统一调整四个卡牌组件的购买流程，删除MissionEconomy导入和扣费校验代码，更新注释说明当前为免费购买模式，简化日志输出内容

assets/script/game/map/SCardComp.ts

@@ -22,7 +22,6 @@ import { oops } from "db://oops-framework/core/Oops";
 import { getCardIconId, setSpriteFrame } from "../common/CardIconHelper";
 import { GameEvent } from "../common/config/GameEvent";
 import { smc } from "../common/SingletonModuleComp";
-import { MissionEconomy } from "./MissionEconomy";
 
 const { ccclass, property } = _decorator;
 
@@ -352,9 +351,10 @@ export class SCardComp extends CCComp {
 
     /**
      * 购买点击处理：
-     *   1. 扣除金币（失败则提示并中止）。
-     *   2. 派发 UseSkillCard 事件，触发技能生效流程。
-     *   3. 播放购买动画，购买后可继续购买（购买按钮保持可见）。
+     *   1. 派发 UseSkillCard 事件，触发技能生效流程。
+     *   2. 播放购买动画，购买后可继续购买（购买按钮保持可见）。
+     *
+     * 注：购买不花费金币（免费获取），原扣费逻辑已移除。
      */
     private onBuyClick() {
         if (!this.cardData) return;
@@ -364,18 +364,6 @@ export class SCardComp extends CCComp {
 
         oops.audio.playEffect("music/button");
 
-        // 扣费
-        const cost = this.cardData.cost ?? 0;
-        const success = MissionEconomy.spendCoin(cost);
-        if (!success) {
-            oops.message.dispatchEvent(GameEvent.ShowSmallTip, "buy_coin");
-            mLogger.log(this.debugMode, "SCardComp", "purchase failed: not enough coin", {
-                uuid: this.cardData.uuid,
-                cost
-            });
-            return;
-        }
-
         smc.vmdata.scores.refresh_hit_count++;
 
         // 派发 UseSkillCard，技能生效流程由 MissSkillsComp 接收处理
@@ -389,8 +377,7 @@ export class SCardComp extends CCComp {
         oops.message.dispatchEvent(GameEvent.CardUsed, this);
 
         mLogger.log(this.debugMode, "SCardComp", "skill card purchased", {
-            uuid: this.cardData.uuid,
-            cost
+            uuid: this.cardData.uuid
         });
     }