Refactor user account management by replacing User entity with UserAccount, updating UserController and UserService for CRUD operations, and modifying MyBatis mappers accordingly.

src/main/resources/mapper/UserMapper.xml

@@ -1,46 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" ?>
-<!DOCTYPE mapper
-        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
-        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
-<mapper namespace="com.gameplatform.server.mapper.UserMapper">
-
-    <resultMap id="UserResultMap" type="com.gameplatform.server.model.User">
-        <id     property="id"         column="id" />
-        <result property="username"   column="username" />
-        <result property="email"      column="email" />
-        <result property="createdAt"  column="created_at" />
-    </resultMap>
-
-    <sql id="Base_Column_List">
-        id, username, email, created_at
-    </sql>
-
-    <select id="findById" parameterType="long" resultMap="UserResultMap">
-        SELECT <include refid="Base_Column_List"/>
-        FROM users
-        WHERE id = #{id}
-    </select>
-
-    <select id="findAll" resultMap="UserResultMap">
-        SELECT <include refid="Base_Column_List"/>
-        FROM users
-        ORDER BY id DESC
-    </select>
-
-    <insert id="insert" parameterType="com.gameplatform.server.model.User" useGeneratedKeys="true" keyProperty="id">
-        INSERT INTO users (username, email, created_at)
-        VALUES (#{username}, #{email}, NOW())
-    </insert>
-
-    <delete id="deleteById" parameterType="long">
-        DELETE FROM users WHERE id = #{id}
-    </delete>
-
-    <update id="update" parameterType="com.gameplatform.server.model.User">
-        UPDATE users
-        SET username = #{username},
-            email = #{email}
-        WHERE id = #{id}
-    </update>
-
-</mapper>