feat: Markdown 편집기 + PDF 변환 파이프라인 + 뷰어 포맷 분기

- Markdown split editor: textarea + marked preview, Ctrl+S 저장
- PUT /api/documents/{id}/content: 원본 파일 저장 + extracted_text 갱신
- GET /api/documents/{id}/preview: PDF 미리보기 캐시 서빙
- preview_worker: LibreOffice headless → PDF 변환 (timeout 60s, retry 1회)
- queue_consumer: preview stage 추가 (embed 후 자동 트리거)
- DocumentViewer: 포맷별 분기 (markdown/pdf/preview-pdf/image/text/cad)
- 오피스/CAD 문서: 새 탭 편집 버튼
- Dockerfile: LibreOffice headless 설치
- migration 005: preview_status, preview_hash, preview_at 컬럼

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

app/workers/preview_worker.py

@@ -0,0 +1,110 @@
+"""PDF 미리보기 생성 워커 — LibreOffice Headless로 문서→PDF 변환"""
+
+import subprocess
+import shutil
+from datetime import datetime, timezone
+from pathlib import Path
+
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from core.config import settings
+from core.utils import setup_logger
+
+logger = setup_logger("preview_worker")
+
+# PDF 변환 대상 포맷
+CONVERTIBLE_FORMATS = {
+    "docx", "xlsx", "pptx", "odt", "ods", "odp",  # 안정 지원
+    "odoc", "osheet", "hwp", "hwpx",                # 검증 필요
+}
+# 이미 PDF이거나 변환 불필요한 포맷
+NATIVE_PDF = {"pdf"}
+NATIVE_IMAGE = {"jpg", "jpeg", "png", "gif", "bmp", "tiff"}
+TEXT_FORMATS = {"md", "txt", "csv", "json", "xml", "html"}
+
+PREVIEW_DIR_NAME = "PKM/.preview"
+TIMEOUT_SECONDS = 60
+
+
+async def process(document_id: int, session: AsyncSession) -> None:
+    """문서 PDF 미리보기 생성"""
+    from models.document import Document
+
+    doc = await session.get(Document, document_id)
+    if not doc:
+        logger.error(f"[preview] document_id={document_id} 없음")
+        return
+
+    fmt = doc.file_format.lower()
+
+    # PDF/이미지/텍스트는 변환 불필요
+    if fmt in NATIVE_PDF or fmt in NATIVE_IMAGE or fmt in TEXT_FORMATS:
+        doc.preview_status = "ready" if fmt in NATIVE_PDF else "none"
+        doc.preview_at = datetime.now(timezone.utc)
+        await session.commit()
+        return
+
+    if fmt not in CONVERTIBLE_FORMATS:
+        doc.preview_status = "none"
+        await session.commit()
+        logger.info(f"[preview] {doc.title} — 변환 불가 포맷: {fmt}")
+        return
+
+    # 원본 파일 경로
+    source = Path(settings.nas_mount_path) / doc.file_path
+    if not source.exists():
+        doc.preview_status = "failed"
+        await session.commit()
+        logger.error(f"[preview] 원본 없음: {source}")
+        return
+
+    # 미리보기 디렉토리
+    preview_dir = Path(settings.nas_mount_path) / PREVIEW_DIR_NAME
+    preview_dir.mkdir(parents=True, exist_ok=True)
+    output_path = preview_dir / f"{document_id}.pdf"
+
+    doc.preview_status = "processing"
+    await session.commit()
+
+    # LibreOffice 변환
+    try:
+        tmp_dir = Path("/tmp/preview_work")
+        tmp_dir.mkdir(exist_ok=True)
+
+        result = subprocess.run(
+            [
+                "libreoffice", "--headless", "--convert-to", "pdf",
+                "--outdir", str(tmp_dir),
+                str(source),
+            ],
+            capture_output=True,
+            text=True,
+            timeout=TIMEOUT_SECONDS,
+        )
+
+        if result.returncode != 0:
+            raise RuntimeError(f"LibreOffice 변환 실패: {result.stderr[:200]}")
+
+        # 변환 결과 찾기
+        converted = tmp_dir / f"{source.stem}.pdf"
+        if not converted.exists():
+            raise RuntimeError(f"변환 결과물 없음: {converted}")
+
+        # 캐시로 이동
+        shutil.move(str(converted), str(output_path))
+
+        doc.preview_status = "ready"
+        doc.preview_hash = doc.file_hash
+        doc.preview_at = datetime.now(timezone.utc)
+        await session.commit()
+        logger.info(f"[preview] {doc.title} → PDF 변환 완료")
+
+    except subprocess.TimeoutExpired:
+        doc.preview_status = "failed"
+        await session.commit()
+        logger.error(f"[preview] {doc.title} — 변환 timeout ({TIMEOUT_SECONDS}s)")
+
+    except Exception as e:
+        doc.preview_status = "failed"
+        await session.commit()
+        logger.error(f"[preview] {doc.title} — 변환 실패: {e}")

app/workers/queue_consumer.py

@@ -11,7 +11,7 @@ from models.queue import ProcessingQueue
 logger = setup_logger("queue_consumer")
 
 # stage별 배치 크기
-BATCH_SIZE = {"extract": 5, "classify": 3, "embed": 1}
+BATCH_SIZE = {"extract": 5, "classify": 3, "embed": 1, "preview": 2}
 STALE_THRESHOLD_MINUTES = 10
 
 
@@ -34,7 +34,7 @@ async def reset_stale_items():
 
 async def enqueue_next_stage(document_id: int, current_stage: str):
     """현재 stage 완료 후 다음 stage를 pending으로 등록"""
-    next_stages = {"extract": "classify", "classify": "embed"}
+    next_stages = {"extract": "classify", "classify": "embed", "embed": "preview"}
     next_stage = next_stages.get(current_stage)
     if not next_stage:
         return
@@ -63,11 +63,13 @@ async def consume_queue():
     from workers.classify_worker import process as classify_process
     from workers.embed_worker import process as embed_process
     from workers.extract_worker import process as extract_process
+    from workers.preview_worker import process as preview_process
 
     workers = {
         "extract": extract_process,
         "classify": classify_process,
         "embed": embed_process,
+        "preview": preview_process,
     }
 
     await reset_stale_items()