diff --git a/yunke-server/app/sync/orchestrator.py b/yunke-server/app/sync/orchestrator.py
index affcf00..303a735 100644
--- a/yunke-server/app/sync/orchestrator.py
+++ b/yunke-server/app/sync/orchestrator.py
@@ -32,7 +32,10 @@ sync continues (the message is still upserted; the watermark still advances).
 Transactions: the orchestrator never commits. Every write is flushed into the
 caller's ``AsyncSession``; the caller owns the commit / rollback. This keeps a
 multi-entity batch atomic at the caller's discretion and lets a test roll a
-failed advance back by simply not committing.
+failed advance back by simply not committing. Exception:
+:func:`sync_call_recordings` commits its own ``SyncRun`` because
+:func:`download_call_recordings` commits per batch internally, so the run
+bookkeeping must land in the same transaction boundary.
 """
 
 from __future__ import annotations
@@ -609,7 +612,11 @@ async def sync_call_recordings(
     caller), this one commits its own ``SyncRun`` row: the underlying
     :func:`download_call_recordings` commits per batch as it advances, so the
     run bookkeeping must land in the same transaction boundary to stay
-    consistent with what was actually persisted.
+    consistent with what was actually persisted. Because it commits internally,
+    it must NOT be added to a batched runner (:func:`_run_all` /
+    :func:`sync_all_wechat`) without reconsidering per-batch atomicity — a
+    batched wrapper can no longer treat the whole entity set as one rollback
+    unit once this func has already persisted its own rows.
 
     Failure policy mirrors every other ``sync_*``: a downloader exception is
     recorded as a ``status='failed'`` ``SyncRun`` and a failed
@@ -634,7 +641,7 @@ async def sync_call_recordings(
     except Exception as exc:
         logger.exception("sync_call_recordings failed")
         await _finish_run(
-            session, run, status="failed", fetched=0, upserted=0, error=str(exc)
+            session, run, status="failed", fetched=0, upserted=0, error=repr(exc)
         )
         await session.commit()
         return SyncResult(
@@ -642,7 +649,7 @@ async def sync_call_recordings(
             status="failed",
             fetched=0,
             upserted=0,
-            error=str(exc),
+            error=repr(exc),
         )
 
 
diff --git a/yunke-server/tests/test_sync_call_recordings.py b/yunke-server/tests/test_sync_call_recordings.py
index 9c59d52..214be26 100644
--- a/yunke-server/tests/test_sync_call_recordings.py
+++ b/yunke-server/tests/test_sync_call_recordings.py
@@ -29,7 +29,6 @@ from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
 
 from app.db.base import Base
 from app.db.models import PhoneCall, SyncRun
-from app.scraper.media import download_call_recordings
 from app.session.yunke_client import YunkeClient
 from app.storage.object_store import ObjectStore
 from app.sync import orchestrator