Third and final leg of the diet_guard -> screen-locker -> wake_alarm
gatelock extraction. WakeAlarm now composes gatelock.GateRoot +
LockWindow(mode="soft") instead of driving tk.Tk() directly, and moves
hardware teardown into on_close() so it runs on every exit path
(including SIGTERM), closing the prior gap where killing the process
left fans maxed. _state.py's HMAC import moves to gatelock.log_integrity,
the last call site of python_pkg.shared.log_integrity, which is deleted.
Manually verified on the real display: fullscreen overlay renders,
xdotool-typed input reaches the dismiss-code Entry (mode="soft" keeps
the existing typing-focus behavior), and SIGTERM exits within ~0.4s
while restoring hardware state. Full repo suite: 949 passed, 100%
branch coverage.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01A7vbgtFfZmfxJtN5DdtJky
