fix(HEL-461): 切换事务失败写入 release-group 审计日志

整组切换中断时除回滚与废弃批次外，同步记录
action=release-group 的失败审计，便于后台追踪。

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>

xiaobai-datahub/datahub/pipeline.py

@@ -813,8 +813,32 @@ class Pipeline:
             try:
                 self._switch_release_group(day, staged)
             except Exception as exc:
+                reason = f"release group switch failed: {exc}"
                 for item in staged.values():
-                    self._abandon_batch(item["batch_id"], f"release group switch failed: {exc}")
+                    self._abandon_batch(item["batch_id"], reason)
+                LOGGER.warning(
+                    "release group switch failed, previous official version keeps serving",
+                    extra={
+                        "hub": {
+                            "trade_date": day,
+                            "datasets": sorted(staged),
+                            "reason": reason,
+                            "event": "release_group_switch_failed",
+                        }
+                    },
+                )
+                self.audit(
+                    "pipeline", "release-group", f"eod:{day}",
+                    json.dumps(
+                        {
+                            "state": "failed",
+                            "reason": reason,
+                            "switched": [],
+                            "force": bool(force),
+                        },
+                        ensure_ascii=False,
+                    ),
+                )
                 raise
             for dataset, item in staged.items():
                 results[dataset] = {