Mirrors the palette rework already applied to diet-guard/dufs-cloud/
screen-locker. Adds `on_fill` (dark) for text drawn on a filled accent/
success/warning/danger surface -- near-white text under-contrasts on all
four (measured 2.2-3.6:1, below the 4.5:1 floor); dark text passes 5.8-9.7:1
on every one of them.
Bumps to 0.1.1 since this is a real release: the 3 consumer repos pin
gatelock to a git tag, not editable.
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.
