Whether the interactive editor prompt has already run for this repo.
Machine-local (not repo-committed): editor choice is a per-developer
preference, not a team-wide setting.
Record that the interactive editor prompt has run, regardless of what
(if anything) the user picked, so gcx init never asks again — use
gcx init --editor <name> to add an assistant later.
Shared model cache directory. On first use, migrate the legacy model cache
out of the durable data directory when a same-filesystem rename is possible.
Wipe per-repository graph data while preserving the advisory ownership
lock inode. Keeping the lock file in place prevents a new daemon from
slipping through while an explicit clean or schema rebuild is in progress.