fix: Codex 리뷰 P1/P2 버그 4건 수정

- [P1] migration runner 도입: schema_migrations 추적, advisory lock,
  단일 트랜잭션 실행, SQL 검증 (기존 DB 업그레이드 대응)
- [P1] eml extract 큐 조건 분기: extract_worker 미지원 포맷 큐 스킵
- [P2] iCalendar escape_ical_text() 추가: RFC 5545 준수
- [P2] 이메일 charset 감지: get_content_charset() 사용 + payload None 방어

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/core/database.py

@@ -1,10 +1,17 @@
 """PostgreSQL 연결 — SQLAlchemy async engine + session factory"""
 
+import logging
+import re
+import time
+from pathlib import Path
+
 from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
 from sqlalchemy.orm import DeclarativeBase
 
 from core.config import settings
 
+logger = logging.getLogger("migration")
+
 engine = create_async_engine(
     settings.database_url,
     echo=False,
@@ -19,12 +26,116 @@ class Base(DeclarativeBase):
     pass
 
 
+# NOTE: 모든 pending migration은 단일 트랜잭션으로 실행됨.
+# DDL이 많거나 대량 데이터 변경이 포함된 migration은 장시간 lock을 유발할 수 있음.
+_MIGRATION_VERSION_RE = re.compile(r"^(\d+)_")
+_MIGRATION_LOCK_KEY = 938475
+
+
+def _parse_migration_files(migrations_dir: Path) -> list[tuple[int, str, Path]]:
+    """migration 파일 스캔 → (version, name, path) 리스트, 버전순 정렬"""
+    files = []
+    for p in sorted(migrations_dir.glob("*.sql")):
+        m = _MIGRATION_VERSION_RE.match(p.name)
+        if not m:
+            continue
+        version = int(m.group(1))
+        files.append((version, p.name, p))
+
+    # 중복 버전 검사
+    seen: dict[int, str] = {}
+    for version, name, _ in files:
+        if version in seen:
+            raise RuntimeError(
+                f"migration 버전 중복: {seen[version]} vs {name} (version={version})"
+            )
+        seen[version] = name
+
+    files.sort(key=lambda x: x[0])
+    return files
+
+
+def _validate_sql_content(name: str, sql: str) -> None:
+    """migration SQL에 BEGIN/COMMIT이 포함되어 있으면 에러 (외부 트랜잭션 깨짐 방지)"""
+    # 주석(-- ...) 라인 제거 후 검사
+    lines = [
+        line for line in sql.splitlines()
+        if not line.strip().startswith("--")
+    ]
+    stripped = "\n".join(lines).upper()
+    for keyword in ("BEGIN", "COMMIT", "ROLLBACK"):
+        # 단어 경계로 매칭 (예: BEGIN_SOMETHING은 제외)
+        if re.search(rf"\b{keyword}\b", stripped):
+            raise RuntimeError(
+                f"migration {name}에 {keyword} 포함됨 — "
+                f"migration SQL에는 트랜잭션 제어문을 넣지 마세요"
+            )
+
+
+async def _run_migrations(conn) -> None:
+    """미적용 migration 실행 (호출자가 트랜잭션 관리)"""
+    from sqlalchemy import text
+
+    # schema_migrations 테이블 생성
+    await conn.execute(text("""
+        CREATE TABLE IF NOT EXISTS schema_migrations (
+            version     INT PRIMARY KEY,
+            name        TEXT NOT NULL,
+            applied_at  TIMESTAMPTZ DEFAULT NOW()
+        )
+    """))
+
+    # advisory lock 획득 (트랜잭션 끝나면 자동 해제)
+    await conn.execute(text(
+        f"SELECT pg_advisory_xact_lock({_MIGRATION_LOCK_KEY})"
+    ))
+
+    # 적용 이력 조회
+    result = await conn.execute(text("SELECT version FROM schema_migrations"))
+    applied = {row[0] for row in result}
+
+    # migration 파일 스캔
+    migrations_dir = Path(__file__).resolve().parent.parent.parent / "migrations"
+    if not migrations_dir.is_dir():
+        logger.info("[migration] migrations/ 디렉토리 없음, 스킵")
+        return
+
+    files = _parse_migration_files(migrations_dir)
+    pending = [(v, name, path) for v, name, path in files if v not in applied]
+
+    if not pending:
+        logger.info("[migration] 미적용 migration 없음")
+        return
+
+    start = time.monotonic()
+    logger.info(f"[migration] {len(pending)}건 적용 시작")
+
+    for version, name, path in pending:
+        sql = path.read_text(encoding="utf-8")
+        _validate_sql_content(name, sql)
+        logger.info(f"[migration] {name} 실행 중...")
+        await conn.execute(text(sql))
+        await conn.execute(
+            text("INSERT INTO schema_migrations (version, name) VALUES (:v, :n)"),
+            {"v": version, "n": name},
+        )
+        logger.info(f"[migration] {name} 완료")
+
+    elapsed = time.monotonic() - start
+    logger.info(f"[migration] 전체 {len(pending)}건 완료 ({elapsed:.1f}s)")
+
+
 async def init_db():
-    """DB 연결 확인 (스키마는 migrations/로 관리)"""
+    """DB 연결 확인 + pending migration 실행"""
     from sqlalchemy import text
 
     async with engine.begin() as conn:
         await conn.execute(text("SELECT 1"))
+        try:
+            await _run_migrations(conn)
+        except Exception as e:
+            logger.error(f"[migration] 실패: {e} — 전체 트랜잭션 롤백")
+            raise
 
 
 async def get_session() -> AsyncSession:

app/core/utils.py

@@ -49,6 +49,20 @@ def count_log_errors(log_path: str) -> int:
 # ─── CalDAV 헬퍼 ───
 
 
+def escape_ical_text(text: str | None) -> str:
+    """iCalendar TEXT 값 이스케이프 (RFC 5545 §3.3.11).
+    SUMMARY, DESCRIPTION, LOCATION 등 TEXT 프로퍼티에 사용.
+    """
+    if not text:
+        return ""
+    text = text.replace("\r\n", "\n").replace("\r", "\n")  # CRLF 정규화
+    text = text.replace("\\", "\\\\")  # 백슬래시 먼저
+    text = text.replace("\n", "\\n")
+    text = text.replace(",", "\\,")
+    text = text.replace(";", "\\;")
+    return text
+
+
 def create_caldav_todo(
     caldav_url: str,
     username: str,
@@ -79,8 +93,8 @@ def create_caldav_todo(
 VERSION:2.0
 BEGIN:VTODO
 UID:{uid}
-SUMMARY:{title}
-DESCRIPTION:{description}
+SUMMARY:{escape_ical_text(title)}
+DESCRIPTION:{escape_ical_text(description)}
 DUE:{due_str}
 STATUS:NEEDS-ACTION
 PRIORITY:5

app/workers/mailplus_archive.py

@@ -139,13 +139,23 @@ async def run():
 
                 # 본문 추출 (텍스트 파트)
                 body = ""
+                charset = None
                 if msg.is_multipart():
                     for part in msg.walk():
                         if part.get_content_type() == "text/plain":
-                            body = part.get_payload(decode=True).decode("utf-8", errors="replace")
+                            payload = part.get_payload(decode=True)
+                            if payload is not None:
+                                charset = part.get_content_charset() or "utf-8"
+                                body = payload.decode(charset, errors="replace")
                             break
                 else:
-                    body = msg.get_payload(decode=True).decode("utf-8", errors="replace")
+                    payload = msg.get_payload(decode=True)
+                    if payload is not None:
+                        charset = msg.get_content_charset() or "utf-8"
+                        body = payload.decode(charset, errors="replace")
+
+                if "\ufffd" in body[:1000]:
+                    logger.debug(f"[메일] charset={charset or 'unknown'} 디코딩 중 replacement 발생")
 
                 # DB 등록
                 rel_path = str(eml_path.relative_to(Path(settings.nas_mount_path)))
@@ -164,11 +174,17 @@ async def run():
                 session.add(doc)
                 await session.flush()
 
-                session.add(ProcessingQueue(
-                    document_id=doc.id, stage="extract", status="pending",
-                ))
+                safe_subj = subject.replace("\n", " ").replace("\r", " ")[:200]
 
-                archived.append(subject)
+                # TODO: extract_worker가 eml 본문/첨부 파싱 지원 시 이 조건 제거
+                if doc.file_format != "eml":
+                    session.add(ProcessingQueue(
+                        document_id=doc.id, stage="extract", status="pending",
+                    ))
+                else:
+                    logger.debug(f"[메일] {safe_subj} — eml extract 미지원, 큐 스킵")
+
+                archived.append(safe_subj)
                 max_uid = max(max_uid, uid)
 
             except Exception as e: