fix: 문서 삭제 시 processing_queue FK 제약 해결 + 변환본/preview 함께 삭제

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

app/api/documents.py

@@ -380,10 +380,25 @@ async def delete_document(
         raise HTTPException(status_code=404, detail="문서를 찾을 수 없습니다")
 
     if delete_file:
+        # 원본 파일 삭제
         file_path = Path(settings.nas_mount_path) / doc.file_path
         if file_path.exists():
             file_path.unlink()
+        # 변환본 삭제
+        if doc.original_path:
+            orig = Path(settings.nas_mount_path) / doc.original_path
+            if orig.exists():
+                orig.unlink()
+        # preview 캐시 삭제
+        preview = Path(settings.nas_mount_path) / "PKM" / ".preview" / f"{doc_id}.pdf"
+        if preview.exists():
+            preview.unlink()
 
+    # 관련 processing_queue 먼저 삭제 (FK 제약)
+    from sqlalchemy import delete as sql_delete
+    await session.execute(
+        sql_delete(ProcessingQueue).where(ProcessingQueue.document_id == doc_id)
+    )
     await session.delete(doc)
     await session.commit()