Return dataframes when submit_query_id is not called

[mare5x]

• With this workaround gpt-oss is now significantly more robust as it often does not call the submit_query_id tool but now we return the latest dataframe anyway.
• Added a gpt-oss:20b config file.

Addresses #84

[kosstbarz]

I think if this change can break our existing use case, when agent asks for a clarification? Do we have this use case in Databao?

[mare5x]

I think if this change can break our existing use case, when agent asks for a clarification? Do we have this use case in Databao?

I don't think that was ever properly discussed (#69). But together with changes from #87 we can sort of handle the issue with output modality hints.

Do you have an idea of how we could detect if the LLM is asking for a clarification vs if the LLM just didn't call submit?

[mare5x]

I was doing some testing and it conveniently turns out that when the LLM asks for clarification (without a tool call), no dataframe will be returned by the workaround in this PR because every ask starts with a init_state which contains df=None. Consequently, a dataframe will only be returned if run_sql_query was executed in the current ask thread.