Release v0.4.0

What's Changed

• back merge : mcp 서버 정상동작 확인 by @gurum505 in #160
• Fix: 디스코드 DM 봇 서버추가 안내 기능 by @AquilaXk in #162
• perf : 채팅 응답 지연 개선 (트랜잭션 경계 축소 + baseline 비동기화) by @hhyukk in #164
• Refactor/front route groups split by @hhyukk in #166
• Feat/error logger by @gurum505 in #168
• Develop by @gurum505 in #169

Full Changelog: v0.3.3...v0.4.0