Function milestone_list_argv 

pub fn milestone_list_argv(slug: &str) -> Vec<String>

Argv for gh api --paginate repos/<slug>/milestones?state=all&per_page=100.

Two contract bits worth pinning:

• state=all — without it, the default endpoint only lists open milestones and gwm milestones push --prune would silently leave closed ones in place.
• --paginate — GitHub caps per_page at 100. Without paginating we’d diff against a truncated remote set for repos with more than 100 milestones, leading to bogus create rows and a dangerously confusing --prune (Copilot review on PR #92).