feat: 투자 소수점 매매 + 카드 할부(installment_months)

- invest_trade.quantity BIGINT→DECIMAL(18,6): 평단·원가·평가/실현손익 계산을 BigDecimal로 전환 (금액은 원단위 정수 유지)
- account_entry.installment_months 추가: 카드 지출 2~24개월 할부 기록(일시불 null), 응답에 포함

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

src/main/resources/db/account.sql

@@ -39,6 +39,7 @@ CREATE TABLE IF NOT EXISTS account_entry (
     memo       VARCHAR(255) NULL,
     wallet_id  BIGINT       NULL COMMENT '발생/출금 계좌(wallet.id)',
     to_wallet_id BIGINT     NULL COMMENT '이체 입금 계좌(TRANSFER)',
+    installment_months INT  NULL COMMENT '카드 할부 개월수(2~24, 일시불은 NULL)',
     created_at DATETIME     NOT NULL DEFAULT CURRENT_TIMESTAMP,
     updated_at DATETIME     NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
     PRIMARY KEY (id),
@@ -48,6 +49,7 @@ CREATE TABLE IF NOT EXISTS account_entry (
 -- 기존 account_entry 컬럼 추가 (멱등)
 ALTER TABLE account_entry ADD COLUMN IF NOT EXISTS wallet_id BIGINT NULL;
 ALTER TABLE account_entry ADD COLUMN IF NOT EXISTS to_wallet_id BIGINT NULL;
+ALTER TABLE account_entry ADD COLUMN IF NOT EXISTS installment_months INT NULL;
 
 -- 가계부 태그 (사용자별 관리 — 게시판 태그와 분리)
 CREATE TABLE IF NOT EXISTS account_tag (
@@ -155,7 +157,7 @@ CREATE TABLE IF NOT EXISTS invest_trade (
     holding_id  BIGINT      NOT NULL COMMENT 'invest_holding.id',
     trade_type  VARCHAR(10) NOT NULL COMMENT 'BUY / SELL',
     trade_date  DATE        NOT NULL,
-    quantity    BIGINT      NOT NULL COMMENT '수량(주)',
+    quantity    DECIMAL(18,6) NOT NULL COMMENT '수량(주, 소수점 매매 지원)',
     price       BIGINT      NOT NULL COMMENT '단가(원)',
     fee         BIGINT      NOT NULL DEFAULT 0 COMMENT '수수료/세금(원)',
     created_at  DATETIME    NOT NULL DEFAULT CURRENT_TIMESTAMP,
@@ -163,3 +165,6 @@ CREATE TABLE IF NOT EXISTS invest_trade (
     KEY idx_trade_member_holding (member_id, holding_id),
     KEY idx_trade_date (holding_id, trade_date, id)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+-- 소수점 매매(예: 해외주식 소수점 매수) 지원: 기존 BIGINT → DECIMAL
+ALTER TABLE invest_trade MODIFY COLUMN quantity DECIMAL(18,6) NOT NULL COMMENT '수량(주, 소수점 매매 지원)';

src/main/resources/mapper/AccountEntryMapper.xml

@@ -15,6 +15,7 @@
         <result property="walletName" column="wallet_name"/>
         <result property="toWalletId" column="to_wallet_id"/>
         <result property="toWalletName" column="to_wallet_name"/>
+        <result property="installmentMonths" column="installment_months"/>
         <result property="createdAt" column="created_at"/>
         <result property="updatedAt" column="updated_at"/>
     </resultMap>
@@ -28,6 +29,7 @@
         e.id, e.member_id, e.entry_date, e.type, e.category, e.amount, e.memo,
         e.wallet_id, w.name AS wallet_name,
         e.to_wallet_id, tw.name AS to_wallet_name,
+        e.installment_months,
         e.created_at, e.updated_at
     </sql>
     <sql id="entryJoins">
@@ -125,15 +127,16 @@
     <insert id="insert" parameterType="com.sb.web.account.domain.AccountEntry"
             useGeneratedKeys="true" keyProperty="id">
         INSERT INTO account_entry (member_id, entry_date, type, category, amount, memo,
-                                   wallet_id, to_wallet_id, created_at, updated_at)
+                                   wallet_id, to_wallet_id, installment_months, created_at, updated_at)
         VALUES (#{memberId}, #{entryDate}, #{type}, #{category}, #{amount}, #{memo},
-                #{walletId}, #{toWalletId}, NOW(), NOW())
+                #{walletId}, #{toWalletId}, #{installmentMonths}, NOW(), NOW())
     </insert>
 
     <update id="update" parameterType="com.sb.web.account.domain.AccountEntry">
         UPDATE account_entry
         SET entry_date = #{entryDate}, type = #{type}, category = #{category},
-            amount = #{amount}, memo = #{memo}, wallet_id = #{walletId}, to_wallet_id = #{toWalletId}
+            amount = #{amount}, memo = #{memo}, wallet_id = #{walletId}, to_wallet_id = #{toWalletId},
+            installment_months = #{installmentMonths}
         WHERE id = #{id} AND member_id = #{memberId}
     </update>