feat(gateway): add reasoning hot reload

Add a /reasoning command across gateway adapters so users can
inspect or change reasoning effort without editing config by hand.

Reload reasoning settings from config.yaml before each agent run,
including background tasks, so the next message picks up the new
value consistently.

gateway/platforms/telegram.py

@@ -159,6 +159,7 @@ class TelegramAdapter(BasePlatformAdapter):
                     BotCommand("new", "Start a new conversation"),
                     BotCommand("reset", "Reset conversation history"),
                     BotCommand("model", "Show or change the model"),
+                    BotCommand("reasoning", "Show or change reasoning effort"),
                     BotCommand("personality", "Set a personality"),
                     BotCommand("retry", "Retry your last message"),
                     BotCommand("undo", "Remove the last exchange"),