Both daemons previously checked /scheme/acpi/thermal (thermald) and
/scheme/acpi/power (redbear-upower) existence with Path::exists or
is_dir, which use stat/lstat. On Redox these syscalls can return
errors for scheme paths even when the scheme IS registered, leading
to false 'unavailable' warnings even after the new acpid thermal/
power directories were added.
Use fs::read_dir (which already worked for actual zone enumeration)
as the existence probe instead. The match expression intentionally
calls read_dir to discard the iterator and keep only the Result;
using ? here would break the warn-once pattern.
vasilito
b8e8774252