fix(file-summary): 修复报告导出下载

review_agent/file_summary/services/report.py

@@ -2,11 +2,13 @@ from __future__ import annotations
 
 from pathlib import Path
 
+from django.conf import settings
+
 from review_agent.models import ExportedSummaryFile, FileSummaryBatch
 
 
 def _exports_dir(batch: FileSummaryBatch) -> Path:
-    root = Path(batch.work_dir or Path("media") / "file_summary" / batch.batch_no)
+    root = Path(batch.work_dir) if batch.work_dir else Path(settings.MEDIA_ROOT) / "file_summary" / batch.batch_no
     export_dir = root / "exports"
     export_dir.mkdir(parents=True, exist_ok=True)
     return export_dir