TEST_OVERRIDE and test_get_override are now #[cfg(test)]-gated and
the read in probe_power_state is wrapped in a #[cfg(test)] block,
so test scaffolding doesn't compile into production builds.
with_override now uses a drop-guard pattern so a panic inside body
still resets TEST_OVERRIDE, preventing stale state from leaking
into subsequent tests.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
3d978e3978