feat: 정기결제 관리 — 구독 현황/해지/재개/플랜변경 백엔드

- member.plan_product, plan_auto_renew 컬럼(구독 상품·자동갱신)
- GET /api/billing/subscription: 플랜·만료일·다음결제일·자동갱신
- POST /api/billing/cancel: 자동갱신 중단(만료일까지 이용), /resume: 재개
- verify 시 상품·자동갱신 기록, 만료 강등·관리자 변경 시 구독정보 정리

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

src/main/resources/mapper/MemberMapper.xml

@@ -17,6 +17,8 @@
         <result property="role" column="role"/>
         <result property="plan" column="plan"/>
         <result property="planExpiresAt" column="plan_expires_at"/>
+        <result property="planProduct" column="plan_product"/>
+        <result property="planAutoRenew" column="plan_auto_renew"/>
         <result property="points" column="points"/>
         <result property="status" column="status"/>
         <result property="createdAt" column="created_at"/>
@@ -24,7 +26,7 @@
     </resultMap>
 
     <sql id="columns">
-        id, login_id, password, name, email, provider, provider_id, google_id, google_picture, profile_image, role, plan, plan_expires_at, points, status, created_at, updated_at
+        id, login_id, password, name, email, provider, provider_id, google_id, google_picture, profile_image, role, plan, plan_expires_at, plan_product, plan_auto_renew, points, status, created_at, updated_at
     </sql>
 
     <select id="findById" parameterType="long" resultMap="memberResultMap">
@@ -97,19 +99,27 @@
         UPDATE member SET role = #{role}, updated_at = NOW() WHERE id = #{id}
     </update>
 
-    <!-- 관리자 수동 변경: 만료일 없이(영구) 설정/해제 -->
+    <!-- 관리자 수동 변경: 만료일/구독정보 없이(영구) 설정/해제 -->
     <update id="updatePlan">
-        UPDATE member SET plan = #{plan}, plan_expires_at = NULL, updated_at = NOW() WHERE id = #{id}
+        UPDATE member SET plan = #{plan}, plan_expires_at = NULL, plan_product = NULL, plan_auto_renew = 0,
+               updated_at = NOW() WHERE id = #{id}
     </update>
 
-    <!-- 결제로 멤버십 부여/갱신: plan + 만료일 -->
+    <!-- 결제로 멤버십 부여/갱신: plan + 만료일 + 구독상품 + 자동갱신 -->
     <update id="updateMembership">
-        UPDATE member SET plan = #{plan}, plan_expires_at = #{expiresAt}, updated_at = NOW() WHERE id = #{id}
+        UPDATE member SET plan = #{plan}, plan_expires_at = #{expiresAt},
+               plan_product = #{product}, plan_auto_renew = #{autoRenew}, updated_at = NOW()
+        WHERE id = #{id}
     </update>
 
-    <!-- 만료된 유료회원 자동 강등 (스케줄러) -->
+    <!-- 구독 해지/재개: 자동 갱신 플래그만 변경 (이용은 만료일까지 유지) -->
+    <update id="updateAutoRenew">
+        UPDATE member SET plan_auto_renew = #{autoRenew}, updated_at = NOW() WHERE id = #{id}
+    </update>
+
+    <!-- 만료된 유료회원 자동 강등 (스케줄러) — 구독정보도 정리 -->
     <update id="downgradeExpired">
-        UPDATE member SET plan = 'FREE', updated_at = NOW()
+        UPDATE member SET plan = 'FREE', plan_product = NULL, plan_auto_renew = 0, updated_at = NOW()
         WHERE plan = 'PREMIUM' AND plan_expires_at IS NOT NULL AND plan_expires_at &lt; NOW()
     </update>