feat(wallet): 新增用户钱包余额查询功能

src/main/java/com/yolo/keyborad/mapper/KeyboardUserWalletMapper.java

@@ -0,0 +1,12 @@
+package com.yolo.keyborad.mapper;
+
+import com.baomidou.mybatisplus.core.mapper.BaseMapper;
+import com.yolo.keyborad.model.entity.KeyboardUserWallet;
+
+/*
+ * @author: ziin
+ * @date: 2025/12/10 18:18
+ */
+
+public interface KeyboardUserWalletMapper extends BaseMapper<KeyboardUserWallet> {
+}