Place timestamp before title in generated filenames for sorting in Explorer view

[ngokevin]

Is your feature request related to a problem? Please describe.

The timestamps are after the generated title. Causing the files in the output folder to not have any order.

Describe the solution you'd like

Filenames should start with the timestamp.

Describe alternatives you've considered

Manual renaming of files.

Additional context

[logancyang]

The conversations are sorted by time in desc in "Load conversation" command, which is its intended usage. I don't plan to change the format of the filename anytime soon because of backward compatibility.