feat: 新增指定目标卡池等级抽卡功能并调整UI布局

- 在drawCardsByRule函数中增加targetPoolLv参数，支持强制从指定等级卡池抽卡
- 修改MissionCardComp中刷新英雄卡牌逻辑，使用targetPoolLv替代heroLv参数
- 调整role_controller.prefab中多个UI元素的位置和尺寸
- 将开始按钮文本从"开始"改为"开始战斗"并加宽按钮

assets/script/game/common/config/CardSet.ts

@@ -224,6 +224,7 @@ export const drawCardsByRule = (
         type?: CardType | CardType[]
         heroType?: HType
         heroLv?: number
+        targetPoolLv?: number
     } = {}
 ): CardConfig[] => {
     const count = Math.max(0, Math.floor(options.count ?? 4))
@@ -233,6 +234,14 @@ export const drawCardsByRule = (
         const typeSet = normalizeTypeFilter(options.type)
         pool = pool.filter(card => typeSet.has(card.type))
     }
+    if (options.targetPoolLv !== undefined) {
+        // 如果指定了目标卡池等级，则强制从所有配置中筛选该等级的卡牌，无视当前的卡池等级限制
+        pool = CardPoolList.filter(card => card.pool_lv === options.targetPoolLv)
+        if (options.type !== undefined) {
+            const typeSet = normalizeTypeFilter(options.type)
+            pool = pool.filter(card => typeSet.has(card.type))
+        }
+    }
     if (options.heroType !== undefined || options.heroLv !== undefined) {
         pool = pool.filter(card => {
             if (card.type !== CardType.Hero) return false