`boot` is the script the README now leads with: curl it, and it installs
git if the machine lacks it, clones the repository to PANAMA_PATH, and
hands off to ./install -- reattaching the terminal first, because a
piped stdin would strand the interview. Deliberately dumb: a curled copy
leaves the repository the moment it runs, so nothing that can drift
lives in it. Re-running is the recovery path: an existing clone is
fast-forwarded, never re-cloned, and a refused fast-forward installs
from what is there rather than stopping mid-repair. All of it pinned by
the boot contract, against stub git and a throwaway clone.
