route method
Decides the verdict. Read ambient values from context at ENTRY (the
effect verb — getInheritedSeedOfExactType); after every await, check
StepArgs.cancel before touching the context again. A THROWING body routes
to supervision as a Failed (the per-work fail-closed posture, ADR-0008
Decision 10) — never an unhandled zone error.
Implementation
@override
Future<RouteVerdict> route(TreeContext context, StepArgs args) async =>
verdict;