feat(email): IMAP ingest service for inbox@hyungi.net

신규 워커 app/workers/inbox_ingest.py (337줄):
- 5분 APScheduler cron (mailplus_archive 와 분리 — INBOX root archive vs DocumentServer/Ingest folder)
- UID SEARCH SINCE 14일 (UNSEEN 단독 의존 X, 사용자가 MailPlus UI 에서 먼저 읽어도 누락 회피)
- Message-ID 정규화 또는 imap:{folder}:{uidvalidity}:{uid} fallback → source_external_id always non-null
- ON CONFLICT DO NOTHING (DB unique 진실원장)
- 신규 row 만 BODY parse: snippet + HTML stripping + attachment metadata (binary 저장 X)
- enqueue_stage(doc.id, classify) 로 기존 classify pipeline 진입
- HC.io heartbeat (옵션, INBOX_INGEST_HC_URL)
- parse 실패 분기: row 생성 전 (logger.error + HC fail) / 후 (email_metadata.parse_error 기록)

env (credentials.env.example):
- INBOX_INGEST_ENABLED=false (기본 dormant, 사용자가 alias/folder 셋업 후 true)
- INBOX_INGEST_FOLDER=DocumentServer/Ingest
- INBOX_INGEST_DAYS=14
- INBOX_INGEST_HC_URL=

main.py:
- inbox_ingest_run import + scheduler.add_job interval 5m

email_ingest 정책 (사용자 라운드 2026-05-12):
- 직접 events row 생성 X
- 이메일은 universal inbox item, source_channel=email memo 로 저장
- classify_worker 가 ai_event_kind 채움 (별 PR 의 4B robustness fix 선결)
- 사용자 1-click promote 만이 events row 생성 path

plan: ~/.claude/plans/document-enchanted-candy.md

app/main.py

@@ -45,6 +45,7 @@ async def lifespan(app: FastAPI):
     from workers.file_watcher import watch_inbox
     from workers.law_monitor import run as law_monitor_run
     from workers.mailplus_archive import run as mailplus_run
+    from workers.inbox_ingest import run as inbox_ingest_run
     from workers.news_collector import run as news_collector_run
     from workers.queue_consumer import consume_queue
     from workers.study_queue_consumer import consume_study_queue
@@ -93,6 +94,9 @@ async def lifespan(app: FastAPI):
     scheduler.add_job(law_monitor_run, CronTrigger(hour=7), id="law_monitor")
     scheduler.add_job(mailplus_run, CronTrigger(hour=7), id="mailplus_morning")
     scheduler.add_job(mailplus_run, CronTrigger(hour=18), id="mailplus_evening")
+    # PR-4: inbox@hyungi.net IMAP ingest (DocumentServer/Ingest 폴더, 5분 cron).
+    # plan: ~/.claude/plans/document-enchanted-candy.md
+    scheduler.add_job(inbox_ingest_run, "interval", minutes=5, id="inbox_ingest")
     scheduler.add_job(daily_digest_run, CronTrigger(hour=20), id="daily_digest")
     scheduler.add_job(global_digest_run, CronTrigger(hour=4, minute=0), id="global_digest")
     scheduler.add_job(morning_briefing_run, CronTrigger(hour=5, minute=10), id="morning_briefing")

app/workers/inbox_ingest.py

@@ -0,0 +1,337 @@
+"""inbox@hyungi.net IMAP ingest 워커 — PR-4 Email Ingest.
+
+Plan: ~/.claude/plans/document-enchanted-candy.md
+
+MailPlus 의 `DocumentServer/Ingest` 폴더 (또는 사용자 지정 폴더) 를 5분 cron 으로
+polling. 메일을 source_channel='email' memo 로 생성하고 classify queue 등록.
+기존 mailplus_archive (INBOX root archive) 와 폴더 분리 + source_external_id dedup 으로
+중복 안 함.
+
+정책 (사용자 라운드 2026-05-12):
+- email_ingest 는 events row 직접 생성 X. memo 만 만들고 사용자 promote 가 events 생성.
+- source_external_id always non-null (Message-ID 정규화 또는 imap:{folder}:{uidvalidity}:{uid}).
+- DB unique index 가 dedup 진실원장. \\Seen flag 는 best-effort.
+- 첨부는 metadata 만, NAS 실 연동은 별 PR.
+"""
+
+import asyncio
+import email
+import hashlib
+import imaplib
+import os
+import re
+from datetime import datetime, timedelta, timezone
+from email.header import decode_header
+from email.utils import parsedate_to_datetime
+from typing import Any
+
+import httpx
+from sqlalchemy import select
+from sqlalchemy.dialects.postgresql import insert as pg_insert
+
+from core.database import async_session
+from core.utils import setup_logger
+from models.automation import AutomationState
+from models.document import Document
+from models.queue import enqueue_stage
+
+logger = setup_logger("inbox_ingest")
+
+_TAG_RE = re.compile(r"<[^>]+>")
+_WS_RE = re.compile(r"[ \t]+")
+_NL_RE = re.compile(r"\n{3,}")
+_MID_BRACKETS = re.compile(r"^<|>$")
+
+
+def _decode_mime_header(raw: str | None) -> str:
+    if not raw:
+        return ""
+    parts = decode_header(raw)
+    out = []
+    for data, charset in parts:
+        if isinstance(data, bytes):
+            out.append(data.decode(charset or "utf-8", errors="replace"))
+        else:
+            out.append(data)
+    return "".join(out)
+
+
+def _normalize_message_id(raw: str | None) -> str | None:
+    if not raw:
+        return None
+    mid = raw.strip()
+    if not mid:
+        return None
+    mid = _MID_BRACKETS.sub("", mid).strip()
+    return mid.lower() or None
+
+
+def _build_source_external_id(message_id: str | None, folder: str, uidvalidity: str, uid: int) -> str:
+    if message_id:
+        return message_id
+    return f"imap:{folder}:{uidvalidity}:{uid}"
+
+
+def _strip_html(html: str) -> str:
+    text = _TAG_RE.sub("", html)
+    text = text.replace("&nbsp;", " ").replace("&amp;", "&").replace("&lt;", "<").replace("&gt;", ">").replace("&quot;", '"').replace("&#39;", "'")
+    text = _WS_RE.sub(" ", text)
+    text = _NL_RE.sub("\n\n", text)
+    return text.strip()
+
+
+def _extract_body(msg: email.message.Message) -> str:
+    text_part = None
+    html_part = None
+    if msg.is_multipart():
+        for part in msg.walk():
+            ctype = part.get_content_type()
+            if part.get("Content-Disposition", "").startswith("attachment"):
+                continue
+            if ctype == "text/plain" and text_part is None:
+                text_part = part
+            elif ctype == "text/html" and html_part is None:
+                html_part = part
+    else:
+        ctype = msg.get_content_type()
+        if ctype == "text/plain":
+            text_part = msg
+        elif ctype == "text/html":
+            html_part = msg
+
+    target = text_part or html_part
+    if target is None:
+        return ""
+    try:
+        payload = target.get_payload(decode=True)
+        if payload is None:
+            return ""
+        charset = target.get_content_charset() or "utf-8"
+        body = payload.decode(charset, errors="replace")
+    except Exception as e:
+        logger.warning(f"[inbox_ingest] body decode 실패: {e}")
+        return ""
+
+    if target.get_content_type() == "text/html":
+        body = _strip_html(body)
+    return body.strip()
+
+
+def _extract_attachments_meta(msg: email.message.Message) -> list[dict]:
+    out: list[dict] = []
+    if not msg.is_multipart():
+        return out
+    for idx, part in enumerate(msg.walk()):
+        disp = part.get("Content-Disposition", "")
+        if not disp.startswith("attachment") and not part.get_filename():
+            continue
+        filename = _decode_mime_header(part.get_filename()) or f"unnamed_{idx}"
+        size: int | None = None
+        try:
+            payload = part.get_payload(decode=True)
+            if payload is not None:
+                size = len(payload)
+        except Exception:
+            size = None
+        out.append({
+            "filename": filename,
+            "mime": part.get_content_type(),
+            "size": size,
+            "part_id": idx,
+        })
+    return out
+
+
+def _parse_received_at(raw: str | None) -> str | None:
+    if not raw:
+        return None
+    try:
+        dt = parsedate_to_datetime(raw)
+        if dt.tzinfo is None:
+            dt = dt.replace(tzinfo=timezone.utc)
+        return dt.astimezone(timezone.utc).isoformat()
+    except Exception:
+        return None
+
+
+def _fetch_uids_sync(host: str, port: int, user: str, password: str, folder: str, since_days: int) -> tuple[str, list[tuple[int, bytes]]]:
+    """동기 IMAP fetch — 폴더 선택 + UID SEARCH SINCE + RFC822 fetch.
+    Returns (uidvalidity_str, [(uid, raw_bytes), ...]).
+    """
+    conn = imaplib.IMAP4_SSL(host, port, timeout=30)
+    try:
+        conn.login(user, password)
+        typ, _ = conn.select(f'"{folder}"')
+        if typ != "OK":
+            raise RuntimeError(f"folder select 실패: {folder}")
+
+        # uidvalidity 추출 (STATUS 또는 SELECT 응답)
+        typ, status_data = conn.status(f'"{folder}"', "(UIDVALIDITY)")
+        uidvalidity = "0"
+        if typ == "OK" and status_data:
+            m = re.search(rb"UIDVALIDITY (\d+)", status_data[0])
+            if m:
+                uidvalidity = m.group(1).decode()
+
+        since = (datetime.now(timezone.utc) - timedelta(days=since_days)).strftime("%d-%b-%Y")
+        typ, data = conn.uid("search", None, f"SINCE {since}")
+        if typ != "OK":
+            return uidvalidity, []
+        uids = data[0].split() if data and data[0] else []
+
+        results = []
+        for uid_bytes in uids:
+            uid = int(uid_bytes)
+            typ, msg_data = conn.uid("fetch", uid_bytes, "(RFC822)")
+            if typ != "OK" or not msg_data or msg_data[0] is None:
+                continue
+            raw = msg_data[0][1]
+            if isinstance(raw, bytes):
+                results.append((uid, raw))
+        return uidvalidity, results
+    finally:
+        try:
+            conn.logout()
+        except Exception:
+            pass
+
+
+async def _heartbeat(url: str | None, success: bool):
+    if not url:
+        return
+    target = url if success else f"{url.rstrip('/')}/fail"
+    try:
+        async with httpx.AsyncClient(timeout=10) as c:
+            await c.get(target)
+    except Exception as e:
+        logger.debug(f"[inbox_ingest] HC heartbeat 실패: {e}")
+
+
+async def run():
+    """5분 cron 진입점 — DocumentServer/Ingest 폴더 polling + memo 생성."""
+    enabled = os.getenv("INBOX_INGEST_ENABLED", "false").lower() == "true"
+    if not enabled:
+        logger.debug("[inbox_ingest] INBOX_INGEST_ENABLED=false, skip")
+        return
+
+    host = os.getenv("MAILPLUS_HOST", "")
+    port = int(os.getenv("MAILPLUS_PORT", "993"))
+    user = os.getenv("MAILPLUS_USER", "")
+    password = os.getenv("MAILPLUS_PASS", "")
+    folder = os.getenv("INBOX_INGEST_FOLDER", "DocumentServer/Ingest")
+    since_days = int(os.getenv("INBOX_INGEST_DAYS", "14"))
+    hc_url = os.getenv("INBOX_INGEST_HC_URL", "").strip() or None
+
+    if not all([host, user, password]):
+        logger.warning("[inbox_ingest] MailPlus 인증 정보 미설정 — skip")
+        return
+
+    try:
+        uidvalidity, emails = await asyncio.to_thread(
+            _fetch_uids_sync, host, port, user, password, folder, since_days,
+        )
+    except Exception as e:
+        logger.error(f"[inbox_ingest] IMAP fetch 실패: {e}")
+        await _heartbeat(hc_url, success=False)
+        return
+
+    if not emails:
+        logger.info("[inbox_ingest] 새 메일 0건")
+        await _heartbeat(hc_url, success=True)
+        return
+
+    created = 0
+    skipped = 0
+    parse_failed = 0
+
+    async with async_session() as session:
+        for uid, raw_bytes in emails:
+            try:
+                msg = email.message_from_bytes(raw_bytes)
+                message_id = _normalize_message_id(msg.get("Message-ID"))
+                source_external_id = _build_source_external_id(message_id, folder, uidvalidity, uid)
+
+                # ON CONFLICT DO NOTHING (DB unique 진실원장)
+                stmt = (
+                    pg_insert(Document)
+                    .values(
+                        file_path=None,
+                        file_hash=hashlib.sha256(raw_bytes).hexdigest(),
+                        file_format="eml",
+                        file_size=len(raw_bytes),
+                        file_type="note",
+                        source_channel="email",
+                        source_external_id=source_external_id,
+                        # 이메일 본문/제목/metadata 는 아래에서 채움 (placeholder 로 일단 row 생성)
+                        title=_decode_mime_header(msg.get("Subject"))[:500] or "(제목없음)",
+                        extracted_text="",
+                        email_metadata={},
+                    )
+                    .on_conflict_do_nothing(
+                        index_elements=["source_external_id"],
+                        index_where="source_channel = 'email' AND source_external_id IS NOT NULL",
+                    )
+                    .returning(Document.id)
+                )
+                result = await session.execute(stmt)
+                row = result.first()
+                if row is None:
+                    skipped += 1
+                    continue
+                doc_id = row[0]
+
+                # 본문/metadata parse (row 생성 후 실패 = email_metadata.parse_error 기록)
+                try:
+                    body = _extract_body(msg)
+                    attachments = _extract_attachments_meta(msg)
+                    metadata: dict[str, Any] = {
+                        "from": _decode_mime_header(msg.get("From")),
+                        "to": [_decode_mime_header(a) for a in msg.get_all("To", [])],
+                        "cc": [_decode_mime_header(a) for a in msg.get_all("Cc", [])],
+                        "subject": _decode_mime_header(msg.get("Subject")),
+                        "folder": folder,
+                        "uidvalidity": uidvalidity,
+                        "uid": uid,
+                        "received_at": _parse_received_at(msg.get("Date")),
+                        "attachments": attachments,
+                    }
+                except Exception as parse_exc:
+                    logger.warning(f"[inbox_ingest] doc {doc_id} parse 실패: {parse_exc}")
+                    body = ""
+                    metadata = {"parse_error": str(parse_exc), "folder": folder, "uidvalidity": uidvalidity, "uid": uid}
+                    parse_failed += 1
+
+                # UPDATE 로 본문/metadata 채움
+                doc = (await session.execute(select(Document).where(Document.id == doc_id))).scalar_one()
+                doc.extracted_text = body
+                doc.email_metadata = metadata
+
+                # classify pipeline 진입 (4B triage fail 상태는 별 PR. ingest 자체는 정상 진행)
+                await enqueue_stage(session, doc_id, "classify")
+                created += 1
+
+            except Exception as e:
+                logger.error(f"[inbox_ingest] UID {uid} 처리 실패: {e}")
+
+        # automation_state 기록 (참고용, dedup 진실원장 아님)
+        state = await session.execute(
+            select(AutomationState).where(AutomationState.job_name == "inbox_ingest")
+        )
+        state_row = state.scalar_one_or_none()
+        now_utc = datetime.now(timezone.utc)
+        if state_row:
+            state_row.last_run_at = now_utc
+            state_row.last_check_value = str(uid) if emails else state_row.last_check_value
+        else:
+            session.add(AutomationState(
+                job_name="inbox_ingest",
+                last_check_value=str(uid) if emails else "0",
+                last_run_at=now_utc,
+            ))
+        await session.commit()
+
+    logger.info(
+        f"[inbox_ingest] folder={folder} fetched={len(emails)} created={created} "
+        f"skipped(dedup)={skipped} parse_failed={parse_failed}"
+    )
+    await _heartbeat(hc_url, success=True)

credentials.env.example

@@ -32,6 +32,13 @@ MAILPLUS_PORT=993
 MAILPLUS_SMTP_PORT=465
 MAILPLUS_USER=hyungi
 MAILPLUS_PASS=
+# PR-4 inbox@hyungi.net IMAP ingest (DocumentServer/Ingest 폴더 → memo).
+# enable 시 INBOX_INGEST_ENABLED=true. 폴더는 alias 수신 메일이 자동 이동되는 곳.
+INBOX_INGEST_ENABLED=false
+INBOX_INGEST_FOLDER=DocumentServer/Ingest
+INBOX_INGEST_DAYS=14
+INBOX_INGEST_HC_URL=
+
 
 # ─── Synology Calendar (CalDAV, 태스크 관리) ───
 CALDAV_URL=https://ds1525.hyungi.net/caldav/