style(tg): перенос длинной строки заголовков ретранслятора

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JY6iWDnGDthdvsMWgK1BMG

tradein-mvp/backend/app/services/tgbot/client.py

@@ -260,7 +260,9 @@ class TelegramClient:
         сбой relay не должен постоянно понижать клиента до прямого пути).
         """
         via_relay = self._relay_base != self._direct_base and url.startswith(self._relay_base)
-        headers = {"X-Relay-Secret": self._relay_secret} if via_relay and self._relay_secret else None
+        headers = (
+            {"X-Relay-Secret": self._relay_secret} if via_relay and self._relay_secret else None
+        )
         try:
             return await client.post(url, json=payload, timeout=timeout, headers=headers)
         except httpx.TransportError: