feat(user-center): 余额卡密兑换移入弹窗并在余额卡片增加入口

- 余额卡片右下角新增「卡密兑换」点击区（data-aksrt-card-pass-open）
- 内联 uc-card-pass 区块替换为 uc-modal 弹窗，兑换逻辑不变
- initCardPass 增加弹窗开关绑定（防重复绑定）
- 清理 :first-child > .uc-card-pass 死选择器片段

assets/css/routes/user-center/credits.css

@@ -30,8 +30,7 @@
 .uc-assets-row--dual > .uc-assets-col {
   display: contents;
 }
-.uc-assets-row--dual > .uc-assets-col:first-child > .uc-asset-card,
-.uc-assets-row--dual > .uc-assets-col:first-child > .uc-card-pass {
+.uc-assets-row--dual > .uc-assets-col:first-child > .uc-asset-card {
   grid-column: 1;
 }
 .uc-assets-row--dual > .uc-assets-col:last-child > .uc-asset-card,

assets/js/credits.js

@@ -271,6 +271,20 @@
 		var roots = document.querySelectorAll('[data-aksrt-card-pass]');
 		if (!roots || !roots.length) return;
 
+		var modal = document.querySelector('[data-aksrt-card-pass-modal]');
+		if (modal) {
+			modal.querySelectorAll('[data-aksrt-card-pass-close]').forEach(function (btn) {
+				if (btn.dataset.aksrtCardPassCloseBound === '1') return;
+				btn.dataset.aksrtCardPassCloseBound = '1';
+				btn.addEventListener('click', function () { closeModal(modal); });
+			});
+		}
+		document.querySelectorAll('[data-aksrt-card-pass-open]').forEach(function (btn) {
+			if (btn.dataset.aksrtCardPassOpenBound === '1') return;
+			btn.dataset.aksrtCardPassOpenBound = '1';
+			btn.addEventListener('click', function () { openModal(modal); });
+		});
+
 		Array.prototype.forEach.call(roots, function (root) {
 			var tip = root.querySelector('[data-aksrt-card-tip]');
 			var busy = false;