Immutable git-tracked files break git tooling. The pre-push ci-mirror gate
runs `pre-commit run --all-files`; end-of-file-fixer opens every file rb+
and dies with "PermissionError: Operation not permitted", so no push from a
normal checkout could ever succeed — every push had to be routed through a
throwaway worktree (a fresh checkout gets new, non-immutable inodes). The
same immutability also breaks pre-commit's unstaged-changes stash: the
`git checkout -- .` unlink fails, the restore never runs, and unrelated
unstaged edits are silently reverted.
Enforcement does not depend on these sources being locked: /etc/hosts is
itself chattr +i, hosts-guard.path watches and re-enforces it via
enforce-hosts.sh against the locked-hosts canonical snapshot, and
hosts-bind-mount.service pins it. Editing the sources changes nothing until
install.sh is re-run as root, which regenerates the guarded artifacts.
Companion to 6e3d61d (same fix for setup_midnight_shutdown.sh).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JsCs1GUyiinA7bg68YvAh1
