More git contexts

[moodymudskipper]

I want to be able to ask :

ask_terminal("checkout bob's latest branch", context = ...)
ask_terminal("close merged branches", context = ...)
...

The full diffs for all the repo might be a bit much given the context window threshold but we should have easy context_*() functions to compose to ask anything.

For sure we need a summary by branch with things like :

• branch name
• branch created from
• author
• date created
• last modified
• number of commits
• maybe a list of commit ids so the llm can cross reference them with other contexts? optional ?
• ...

so maybe context_git_branch(), context_git_branches() and a general context_git() with parameters.