Function current_phase_label 

pub fn current_phase_label() -> Option<Cow<'static, str>>

Snapshot the active phase label installed by the most recent PhaseGuard::install on this thread. None outside any guarded scope. Construction sites for AssertDetail / PassDetail / InfoNote call this to auto-stamp the phase field; the test author can still override via the builder with_phase(...) chain when an explicit value is preferred.