feat: 게시판 추천/비추천 + 작성자 아바타 + 추천자 + 활동 포인트

- 작성자 아바타: post/comment 조회 시 member JOIN(google_picture/profile_image),
  목록·상세·댓글 응답에 노출
- 추천/비추천: post_vote/comment_vote 테이블 + 토글 API
  (POST /board/posts|comments/{id}/vote), 게시글/댓글 응답에 up/down/myVote
- 추천자 목록: GET /board/posts/{id}/recommenders + PostDetail.recommenders
- 포인트: member.points + point_history. 글/댓글 작성 시 10P, 하루 3회 한도(합산).
  PointService, GET /auth/points, MemberResponse.points 노출
- @MapperScan 에 point.mapper 추가, AuthController WebMvc 테스트 MockBean 보강

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/main/resources/mapper/PointMapper.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
+        "https://mybatis.org/dtd/mybatis-3-mapper.dtd">
+<mapper namespace="com.sb.web.point.mapper.PointMapper">
+
+    <select id="countTodayGrants" resultType="int">
+        SELECT COUNT(*) FROM point_history
+        WHERE member_id = #{memberId} AND reason = #{reason} AND created_at &gt;= CURDATE()
+    </select>
+
+    <insert id="insertHistory">
+        INSERT INTO point_history (member_id, amount, reason, created_at)
+        VALUES (#{memberId}, #{amount}, #{reason}, NOW())
+    </insert>
+
+    <update id="addPoints">
+        UPDATE member SET points = points + #{amount}, updated_at = NOW() WHERE id = #{memberId}
+    </update>
+
+    <select id="getPoints" parameterType="long" resultType="long">
+        SELECT points FROM member WHERE id = #{memberId}
+    </select>
+
+</mapper>