Sessions on their own branch, merged back when you say
Ask for a session on its own git branch and it works in a worktree beside your project. Background sessions now run in the same sandbox as your chat.
Work apart, merge when ready
Ask the agent for a session on its own branch and it opens one in a git worktree beside your project, so its edits never touch your main checkout. The sidebar keeps it under the same project.
When you ask, the agent commits what that session left and merges its branch into your project. If your project has uncommitted changes it stops and says so; if the branches conflict, the merge is undone and you get the list of files.
Sub-sessions and sessions started on a brief used to run their shell commands outside the sandbox. They now use the same one as your chat: writes stay in the project, temp and download caches.