EnterWorktree can resolve a repo root from a non-git working copy (code path compiled out)

EnterWorktree is the tool that moves a session into a git worktree, an extra working copy of a repository. Its code now includes a fallback to a workingCopyRoot when there is no git root. That branch is switched off in the built program and never runs. A related lookup elsewhere always finds nothing. The error message shown when a folder is the main working tree is unchanged.