feat(shop): 포인트 상점 구현 — 계좌 슬롯(500P)·AI 통계 크레딧(1000P→10회)

- member 테이블: extra_wallet_slots, ai_stat_credits 컬럼 추가(ALTER IF NOT EXISTS)
- MemberMapper: 상점 관련 5개 메서드 추가(getExtraWalletSlots/getAiStatCredits/incrementExtraWalletSlots/addAiStatCredits/decrementAiStatCredit)
- ShopService: buyWalletSlot(500P, max 3개), buyAiStatPack(1000P→10회) 구현
- ShopController: GET /api/account/shop/status, POST /api/account/shop/buy
- AccountService.freeWalletLimit: bonus=0 TODO → memberMapper.getExtraWalletSlots 실제 조회
- AccountService.aiComment: FREE 회원 크레딧 차감 로직 추가, 소진 시 402 반환
- AccountController.aiComment: current 파라미터 전달
- WebConfig: /api/account/ai-comment 를 premiumInterceptor 에서 제거(서비스 레이어에서 처리)
- BackupController: @DeleteMapping import 누락 수정

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/main/java/com/sb/web/account/controller/AccountController.java

@@ -252,12 +252,12 @@ public class AccountController {
         return accountService.parseText(req);
     }
 
-    /** 통계 화면 집계 → AI 재무 코멘트(유료). 집계만 전송, 거래 원문 미전송. */
+    /** 통계 화면 집계 → AI 재무 코멘트. PREMIUM 무제한, FREE 는 크레딧 차감. */
     @PostMapping("/ai-comment")
     public com.sb.web.account.dto.AiCommentResponse aiComment(
             @RequestBody com.sb.web.account.dto.AiCommentRequest req,
             @RequestAttribute(AuthInterceptor.CURRENT_MEMBER) SessionUser current) {
-        return accountService.aiComment(req);
+        return accountService.aiComment(req, current);
     }
 
     /** 미확인 내역 확정 (분류/계좌 보정) */

src/main/java/com/sb/web/account/controller/BackupController.java

@@ -6,10 +6,11 @@ import com.sb.web.auth.dto.SessionUser;
 import com.sb.web.auth.web.AuthInterceptor;
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestAttribute;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestAttribute;
 import org.springframework.web.bind.annotation.RestController;
 
 /**

src/main/java/com/sb/web/account/controller/ShopController.java

@@ -0,0 +1,37 @@
+package com.sb.web.account.controller;
+
+import com.sb.web.account.dto.ShopStatusResponse;
+import com.sb.web.account.service.ShopService;
+import com.sb.web.auth.dto.SessionUser;
+import com.sb.web.auth.web.AuthInterceptor;
+import lombok.RequiredArgsConstructor;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.Map;
+
+@RestController
+@RequestMapping("/api/account/shop")
+@RequiredArgsConstructor
+public class ShopController {
+
+    private final ShopService shopService;
+
+    @GetMapping("/status")
+    public ShopStatusResponse status(
+            @RequestAttribute(AuthInterceptor.CURRENT_MEMBER) SessionUser current) {
+        return shopService.getStatus(current.getId());
+    }
+
+    @PostMapping("/buy")
+    public ShopStatusResponse buy(
+            @RequestBody Map<String, String> body,
+            @RequestAttribute(AuthInterceptor.CURRENT_MEMBER) SessionUser current) {
+        String item = body.get("item");
+        return switch (item) {
+            case "WALLET_SLOT" -> shopService.buyWalletSlot(current.getId());
+            case "AI_STAT"     -> shopService.buyAiStatPack(current.getId());
+            default -> throw new org.springframework.web.server.ResponseStatusException(
+                    org.springframework.http.HttpStatus.BAD_REQUEST, "SHOP_UNKNOWN_ITEM");
+        };
+    }
+}

src/main/java/com/sb/web/account/dto/ShopStatusResponse.java

@@ -0,0 +1,15 @@
+package com.sb.web.account.dto;
+
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+@Builder
+public class ShopStatusResponse {
+    private int extraWalletSlots;
+    private int aiStatCredits;
+    private int maxExtraSlots;
+    private int walletSlotPrice;
+    private int aiStatPrice;
+    private int aiStatPackSize;
+}

src/main/java/com/sb/web/account/service/AccountService.java

@@ -21,6 +21,8 @@ import com.sb.web.account.dto.WalletResponse;
 import com.sb.web.account.mapper.AccountEntryMapper;
 import com.sb.web.account.mapper.AccountTagMapper;
 import com.sb.web.account.mapper.WalletMapper;
+import com.sb.web.auth.dto.SessionUser;
+import com.sb.web.auth.mapper.MemberMapper;
 import com.sb.web.common.exception.ApiException;
 import com.sb.web.point.PointService;
 import lombok.RequiredArgsConstructor;
@@ -51,6 +53,7 @@ public class AccountService {
     private final CardNotificationParser notificationParser;
     private final AiEntryParser aiEntryParser;
     private final PointService pointService;
+    private final MemberMapper memberMapper;
 
     /* ===================== 항목 ===================== */
 
@@ -341,11 +344,26 @@ public class AccountService {
                 .build();
     }
 
-    /** 통계 화면 집계 → AI 재무 코멘트. 집계만 JSON 으로 직렬화해 전달(거래 원문 미전송). 미설정/실패 시 빈 코멘트. */
-    public com.sb.web.account.dto.AiCommentResponse aiComment(com.sb.web.account.dto.AiCommentRequest req) {
+    /** 통계 화면 집계 → AI 재무 코멘트.
+     *  - PREMIUM: 무제한.
+     *  - FREE + ai_stat_credits > 0: 크레딧 1 차감 후 호출.
+     *  - FREE + credits == 0: 402 에러(프론트가 상점으로 유도).
+     */
+    @Transactional
+    public com.sb.web.account.dto.AiCommentResponse aiComment(
+            com.sb.web.account.dto.AiCommentRequest req, SessionUser current) {
+        if ("FREE".equals(current.getPlan())) {
+            int credits = memberMapper.getAiStatCredits(current.getId());
+            if (credits <= 0) {
+                throw new ApiException(HttpStatus.PAYMENT_REQUIRED, "AI_STAT_CREDIT_EMPTY");
+            }
+            memberMapper.decrementAiStatCredit(current.getId());
+        }
         try {
             String json = new com.fasterxml.jackson.databind.ObjectMapper().writeValueAsString(req);
             return aiEntryParser.financeComment(json);
+        } catch (ApiException e) {
+            throw e;
         } catch (Exception e) {
             return com.sb.web.account.dto.AiCommentResponse.builder()
                     .bullets(java.util.List.of()).tips(java.util.List.of()).build();
@@ -561,9 +579,9 @@ public class AccountService {
     public static final int FREE_WALLET_BASE_LIMIT = 2;
     public static final int FREE_WALLET_MAX_LIMIT  = 5;
 
-    /** 무료 회원의 해당 타입 등록 한도 = 기본 2 + 구매한 영구 보너스 슬롯(추후 상점), 최대 5. */
+    /** 무료 회원의 해당 타입 등록 한도 = 기본 2 + 포인트 상점 구매 슬롯, 최대 5. */
     private int freeWalletLimit(Long memberId, String type) {
-        int bonus = 0; // TODO: 포인트 상점 구현 시 회원×종류별 구매 슬롯 수를 조회해 더함
+        int bonus = memberMapper.getExtraWalletSlots(memberId);
         return Math.min(FREE_WALLET_BASE_LIMIT + bonus, FREE_WALLET_MAX_LIMIT);
     }
 

src/main/java/com/sb/web/account/service/ShopService.java

@@ -0,0 +1,71 @@
+package com.sb.web.account.service;
+
+import com.sb.web.account.dto.ShopStatusResponse;
+import com.sb.web.auth.mapper.MemberMapper;
+import com.sb.web.point.PointService;
+import com.sb.web.point.mapper.PointMapper;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.web.server.ResponseStatusException;
+
+@Service
+@RequiredArgsConstructor
+public class ShopService {
+
+    static final int MAX_EXTRA_SLOTS   = 3;
+    static final int WALLET_SLOT_PRICE = 500;
+    static final int AI_STAT_PRICE     = 1000;
+    static final int AI_STAT_PACK_SIZE = 10;
+
+    private static final String REASON_SHOP_WALLET_SLOT = "SHOP_WALLET_SLOT";
+    private static final String REASON_SHOP_AI_STAT     = "SHOP_AI_STAT";
+
+    private final MemberMapper memberMapper;
+    private final PointMapper  pointMapper;
+
+    public ShopStatusResponse getStatus(Long memberId) {
+        return ShopStatusResponse.builder()
+                .extraWalletSlots(memberMapper.getExtraWalletSlots(memberId))
+                .aiStatCredits(memberMapper.getAiStatCredits(memberId))
+                .maxExtraSlots(MAX_EXTRA_SLOTS)
+                .walletSlotPrice(WALLET_SLOT_PRICE)
+                .aiStatPrice(AI_STAT_PRICE)
+                .aiStatPackSize(AI_STAT_PACK_SIZE)
+                .build();
+    }
+
+    @Transactional
+    public ShopStatusResponse buyWalletSlot(Long memberId) {
+        int slots = memberMapper.getExtraWalletSlots(memberId);
+        if (slots >= MAX_EXTRA_SLOTS) {
+            throw new ResponseStatusException(HttpStatus.CONFLICT, "SHOP_WALLET_SLOT_MAX");
+        }
+        long points = pointService(memberId);
+        if (points < WALLET_SLOT_PRICE) {
+            throw new ResponseStatusException(HttpStatus.PAYMENT_REQUIRED, "SHOP_NOT_ENOUGH_POINTS");
+        }
+        pointMapper.insertHistory(memberId, -WALLET_SLOT_PRICE, REASON_SHOP_WALLET_SLOT);
+        pointMapper.addPoints(memberId, -WALLET_SLOT_PRICE);
+        memberMapper.incrementExtraWalletSlots(memberId);
+        return getStatus(memberId);
+    }
+
+    @Transactional
+    public ShopStatusResponse buyAiStatPack(Long memberId) {
+        long points = pointService(memberId);
+        if (points < AI_STAT_PRICE) {
+            throw new ResponseStatusException(HttpStatus.PAYMENT_REQUIRED, "SHOP_NOT_ENOUGH_POINTS");
+        }
+        pointMapper.insertHistory(memberId, -AI_STAT_PRICE, REASON_SHOP_AI_STAT);
+        pointMapper.addPoints(memberId, -AI_STAT_PRICE);
+        memberMapper.addAiStatCredits(memberId, AI_STAT_PACK_SIZE);
+        return getStatus(memberId);
+    }
+
+    private long pointService(Long memberId) {
+        Long p = pointMapper.getPoints(memberId);
+        return p == null ? 0L : p;
+    }
+}

src/main/java/com/sb/web/auth/mapper/MemberMapper.java

@@ -73,4 +73,11 @@ public interface MemberMapper {
     int updateStatus(@Param("id") Long id, @Param("status") String status);
 
     int deleteById(@Param("id") Long id);
+
+    // ── 포인트 상점 ──────────────────────────────────────────────
+    int getExtraWalletSlots(@Param("id") Long id);
+    int getAiStatCredits(@Param("id") Long id);
+    int incrementExtraWalletSlots(@Param("id") Long id);
+    int addAiStatCredits(@Param("id") Long id, @Param("amount") int amount);
+    int decrementAiStatCredit(@Param("id") Long id);
 }

src/main/java/com/sb/web/common/config/WebConfig.java

@@ -39,7 +39,6 @@ public class WebConfig implements WebMvcConfigurer {
                 .addPathPatterns(
                         "/api/account/stats",
                         "/api/account/category-stats",
-                        "/api/account/ai-comment",
                         "/api/account/networth/trend",
                         "/api/account/budgets", "/api/account/budgets/**",
                         "/api/account/ocr", "/api/account/ocr/**",

src/main/resources/db/member.sql

@@ -65,6 +65,10 @@ CREATE TABLE IF NOT EXISTS iap_purchase (
     KEY idx_iap_member (member_id)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
 
+-- 포인트 상점: 추가 계좌 슬롯(무료 회원 500P/개, 최대 3개), AI 통계 크레딧(1000P → 10회)
+ALTER TABLE member ADD COLUMN IF NOT EXISTS extra_wallet_slots INT NOT NULL DEFAULT 0 COMMENT '포인트 상점 구매 추가 계좌 슬롯 수 (최대 3)' AFTER points;
+ALTER TABLE member ADD COLUMN IF NOT EXISTS ai_stat_credits INT NOT NULL DEFAULT 0 COMMENT '포인트 상점 구매 AI 통계 크레딧 잔여 횟수' AFTER extra_wallet_slots;
+
 -- 포인트 적립/차감 이력 (감사 + 일일 지급 한도 계산용).
 CREATE TABLE IF NOT EXISTS point_history (
     id         BIGINT      NOT NULL AUTO_INCREMENT,

src/main/resources/mapper/MemberMapper.xml

@@ -152,4 +152,21 @@
         DELETE FROM member WHERE id = #{id}
     </delete>
 
+    <!-- 포인트 상점 -->
+    <select id="getExtraWalletSlots" resultType="int">
+        SELECT COALESCE(extra_wallet_slots, 0) FROM member WHERE id = #{id}
+    </select>
+    <select id="getAiStatCredits" resultType="int">
+        SELECT COALESCE(ai_stat_credits, 0) FROM member WHERE id = #{id}
+    </select>
+    <update id="incrementExtraWalletSlots">
+        UPDATE member SET extra_wallet_slots = extra_wallet_slots + 1, updated_at = NOW() WHERE id = #{id}
+    </update>
+    <update id="addAiStatCredits">
+        UPDATE member SET ai_stat_credits = ai_stat_credits + #{amount}, updated_at = NOW() WHERE id = #{id}
+    </update>
+    <update id="decrementAiStatCredit">
+        UPDATE member SET ai_stat_credits = GREATEST(0, ai_stat_credits - 1), updated_at = NOW() WHERE id = #{id}
+    </update>
+
 </mapper>