CngxStepErrorContext

Context passed to the *cngxStepError template. Renders the validation-error reason for a step in the error state - sibling of the commit-channel *cngxStepRejection slot. The two channels stay distinct: rejection decorates the step a commit rolled back FROM; this slot surfaces the per-step validation message.

message resolves the direct [error] string > the first aggregator label > the i18n errored status phrase, so a template that renders {{ message }} always shows a non-empty reason. errorLabels / announcement expose the richer aggregator surface for consumers that want a list or the full SR phrase.