Gemini cli support and no pagination

[gnyman]

(Note: This mixes two different things, if it's a problem and you think one or both of them is worth merging I can break it out into two different PR's).

First, it adds support for generating transcripts for gemini. When prompting you to select a session it will list them together and prefix gemini sessions with [gem] and claude with [cld].

The second thing it does it make pagination optional and defaults to one big file. Browsers and computers are really fast nowadays and will have no problem rendering big files so personally I don't see any value in paginating it. As a bonus it allows searching using the native search (though I see you already solved that).

[gnyman]

Actually when working on another change I noticed the pagination did not work as I thought, I had not looked close enough at the original solution but jumped straight into solving a problem that did not really exist (too easy to do nowadays and the agents are unlikely to try to try to speak up on bad instructions).

I removed that one, I'll do another PR with that as I still think pagination is unnecessary but it did not belong in this PR at least.

[almartin82]

+1 on having an option to remove pagination