Move FIFO setup and percentage emission into helper scripts so the
Hyprland config has no raw $VAR references — Hyprland's parser
substitutes $varname at parse time, which mangled awk's $2 and
$HYPRLAND_INSTANCE_SIGNATURE and left binds broken after reload.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
