Add option for automatic summary of transcriptions

[EdrisT]

I think having the option to enable automatic summary of transcriptions using the default summary profile would be a useful feature. Especially when used in combination with the automatic transcription on upload option.

The option could be enabled with a radio button in the LLM settings similar to the auto transcription on upload.

The option should probably be greyed out if the LLM endpoint is not configured.

I think having this option would also be beneficial if/when automatic export/mail delivery (#211) gets implemented since we could have the summaries included in the export/mail delivery.

[rishikanthc]

I agree. This would be a useful convenience feature to add.. Will add this to the plan