Added Gemini CLI as an opt-in module

[cassmtnr]

I used Claude Flow to implement Gemini CLI as an opt-in module in Claude Flow, I am now testing it, it's fully documented in this PR, and inside the src/modules/gemini-cli folder in my fork.

I just rebased with ruvnet/claude-flow@2.7.47 and renamed to 2.7.47-gemini on my fork. I didn't fully test after rebasing, gonna do it soon.

To be honest I am still struggling to understand the additional commands from Claude Flow and now from Gemini CLI as well.

With Claude Flow I usually start with the hive mind wizard, same with this new module, after the Gemini CLI authentication, I start the hive mind wizard in an existing project and for the swarm description I tell it to do a deep analysis in the project and then await new prompts for implementations and maintenance.