Error "Could not determine chat role" when sending too many messages to a single chat

[igrmk]

I have an alias set up to use the predefined role using the --chat option.
For example, --chat improve is automatically added to every "Improve writing" query.

ShellGPT truncates the chat using the CHAT_CACHE_LENGTH option
each time it saves the conversation.

As a result, the first message eventually gets removed,
causing the tool to display "Could not determine chat role",
since the role is defined in that initial message.

To prevent this issue, the first message should likely never be truncated.