Switch between local and worktree if no changes

[notkainoa]

In a thread if the agent hasn't made any changes yet, it would be nice if I could still switch between local and worktree.

[Noisemaker111]

I like this idea and would personally use it, so here is a prompt that would make this possible

Change local/worktree switching so the env toggle is not locked by first message, first response, or active session state, and instead only becomes permanently locked once the thread has real file edits. Persist env mode as per-thread state even after a thread becomes server-backed, so a text-only exchange like ‘hi’ does not lose the user’s ability to switch from local to worktree. The Local/New worktree toggle should remain clickable during and after no-edit turns, although branch/worktree selection actions can still be guarded while a turn is actively running. If the user switches to worktree before any file edits exist and no worktree is attached yet, the next send should create the worktree first rather than requiring this to be the literal first message in the thread. Also treat cwd/worktree changes as a provider-session restart condition so the next turn always runs in the newly selected workspace.