feat: 투자 매매내역 수정 API (PUT /trades/{id})

- InvestController/Service/Mapper: updateTrade 추가
- 수정 결과를 시점별로 시뮬레이션해 보유수량이 음수가 되면 거부(매도 과다 방지)

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

src/main/resources/mapper/InvestMapper.xml

@@ -87,6 +87,13 @@
         VALUES (#{memberId}, #{holdingId}, #{tradeType}, #{tradeDate}, #{quantity}, #{price}, #{fee}, NOW())
     </insert>
 
+    <update id="updateTrade" parameterType="com.sb.web.account.domain.InvestTrade">
+        UPDATE invest_trade
+        SET trade_type = #{tradeType}, trade_date = #{tradeDate},
+            quantity = #{quantity}, price = #{price}, fee = #{fee}
+        WHERE id = #{id} AND member_id = #{memberId}
+    </update>
+
     <delete id="deleteTrade">
         DELETE FROM invest_trade WHERE id = #{id} AND member_id = #{memberId}
     </delete>