An agent that edits files needs somewhere to edit them. Your working copy is the obvious place and the wrong one.
Tick run in its own git worktree when you create a session and it works in a sibling worktree on its own branch. Your checkout is untouched, and two sessions on the same machine do not fight over the same files.
Cleaning up
Worktrees accumulate. The console can survey a machine’s worktrees and discard the ones that are safe to lose — where the machine decides what is safe, not the console, and shows the reason rather than restating the rule.
A worktree is held back when it has uncommitted changes, when it carries commits of its own, or when a session is still live in it.
One thing to know
Discarding the worktree of an ended session strands that conversation permanently: a resume cannot be pointed at a different directory. The survey tells you which worktrees are in that position. This is a known limitation rather than a solved problem.