Initialize the foreground-daemon process. Commits the XDG layout pin (and
drains a residual ~/.lean-ctx) before the daemon writes anything, so this
long-running, possibly launchd/systemd-autostarted writer can never
re-collapse config/data/state/cache onto a stray legacy dir (GL #623). The
MCP server pins on its own start; the daemon is the other independent entry
point (e.g. serve --_foreground-daemon), so it must heal too. heal() is
idempotent and cheap — a no-op once pinned and when no residual dir exists.