fix(gateway): make Telegram DM topic config writes atomic

gateway/platforms/telegram.py

@@ -11,6 +11,7 @@ import asyncio
 import json
 import logging
 import os
+import tempfile
 import html as _html
 import re
 from typing import Dict, List, Optional, Any
@@ -534,8 +535,23 @@ class TelegramAdapter(BasePlatformAdapter):
                         break
 
             if changed:
-                with open(config_path, "w") as f:
-                    _yaml.dump(config, f, default_flow_style=False, sort_keys=False)
+                fd, tmp_path = tempfile.mkstemp(
+                    dir=str(config_path.parent),
+                    suffix=".tmp",
+                    prefix=".config_",
+                )
+                try:
+                    with os.fdopen(fd, "w", encoding="utf-8") as f:
+                        _yaml.dump(config, f, default_flow_style=False, sort_keys=False)
+                        f.flush()
+                        os.fsync(f.fileno())
+                    os.replace(tmp_path, config_path)
+                except BaseException:
+                    try:
+                        os.unlink(tmp_path)
+                    except OSError:
+                        pass
+                    raise
                 logger.info(
                     "[%s] Persisted thread_id=%s for topic '%s' in config.yaml",
                     self.name, thread_id, topic_name,