fix(gateway): atomic writes for sibling recovery/dedup state files

Widen PR #17842's atomic-write fix to two sibling sites that exhibit the
same 'partial JSON on interrupted write' class of bug:

- gateway/platforms/feishu.py: dedup state (_dedup_state_path)
- gateway/platforms/helpers.py: ParticipatedThreadTracker save

Both are small recovery/coordination files that get rewritten frequently and
break cross-restart dedup if left partial.

gateway/platforms/feishu.py

@@ -141,6 +141,7 @@ from gateway.platforms.base import (
 )
 from gateway.status import acquire_scoped_lock, release_scoped_lock
 from hermes_constants import get_hermes_home
+from utils import atomic_json_write
 
 logger = logging.getLogger(__name__)
 
@@ -3804,7 +3805,7 @@ class FeishuAdapter(BasePlatformAdapter):
             recent = self._seen_message_order[-self._dedup_cache_size:]
             # Save as {msg_id: timestamp} so TTL filtering works across restarts.
             payload = {"message_ids": {k: self._seen_message_ids[k] for k in recent if k in self._seen_message_ids}}
-            self._dedup_state_path.write_text(json.dumps(payload, ensure_ascii=False), encoding="utf-8")
+            atomic_json_write(self._dedup_state_path, payload, indent=None)
         except OSError:
             logger.warning("[Feishu] Failed to persist dedup state to %s", self._dedup_state_path, exc_info=True)
 

gateway/platforms/helpers.py

@@ -13,6 +13,8 @@ import time
 from pathlib import Path
 from typing import TYPE_CHECKING, Dict
 
+from utils import atomic_json_write
+
 if TYPE_CHECKING:
     from gateway.platforms.base import MessageEvent
 
@@ -237,12 +239,11 @@ class ThreadParticipationTracker:
 
     def _save(self) -> None:
         path = self._state_path()
-        path.parent.mkdir(parents=True, exist_ok=True)
         thread_list = list(self._threads)
         if len(thread_list) > self._max_tracked:
             thread_list = thread_list[-self._max_tracked:]
             self._threads = set(thread_list)
-        path.write_text(json.dumps(thread_list), encoding="utf-8")
+        atomic_json_write(path, thread_list, indent=None)
 
     def mark(self, thread_id: str) -> None:
         """Mark *thread_id* as participated and persist."""