Extracted and generalized from diet_guard's existing tombstone-merge scheme
and GitHub Contents API client, extended with per-field HLC LWW so the same
library can also cover todo's mutable notes and wake_alarm's single-value
sync (Workstream D scoping decision, 2026-07-04). 100% branch coverage,
clean ruff/mypy/pylint/bandit.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017McuA1nAi6jBT1EaS5BrVf
Extracts the chattr+bind-mount+systemd-watcher file-locking pattern (and a
new pacman PreTransaction package-block primitive) out of screen-locker and
steam-backlog-enforcer into a standalone, config-driven library so both
projects (and steam-backlog-enforcer's new block-gaming feature) can share
one implementation instead of maintaining parallel copies.
- guardctl: CLI entry point (file-guard, package-block subcommands)
- lib/file_guard.sh: chattr +i / bind-mount / systemd-path-watcher / pacman
hook enforcement for a single target file, keyed by /etc/guard-lib/targets
config; includes `sync` (adopt current content as canonical - for a
caller's own legitimate edit) distinct from `pacman-relock` (revert drift)
- lib/package_block.sh: time-locked pacman PreTransaction hook that refuses
to (re)install a given package while a lock file's `until` timestamp is in
the future; supports --bind-mount to compose with file-guard on the same
lock file
- pacman-hooks/: the installed hook scripts + .hook definitions
- systemd/: guard-file@.path/.service watcher units, guard-bind-mount@.service
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AFNiYQQgSLAkiBXswyimPq
Extracted from wake_alarm, screen-locker, and diet_guard, which each
independently implemented fullscreen-lock, input-grab, VT-disable, and
HMAC-signed-state mechanics at different levels of maturity (the HMAC
module was already a hand-copied duplicate between two of them).
LockConfig exposes overrideredirect/grab/disable_vt as independent
axes so one LockWindow can reproduce all three projects' exact prior
behavior, plus screen-locker's confirmed upgrade to retry-forever grab.
