Scope
Expand the messaging backplane demo so it reads like an app-native messaging platform setup rather than a low-level transport sample.
Acceptance criteria
- Add a host/builder startup surface similar in shape to MassTransit/MediatR composition.
- Expose a typed client for request/reply and publish/subscribe use from application services.
- Keep the broker boundary pluggable through application-owned transports.
- Preserve PatternKit's role as pattern API/DSL/composition, not broker infrastructure.
- Add tests for host setup/topology plus the existing end-to-end workflow.
- Update docs to show the richer setup and adapter boundary.
Scope
Expand the messaging backplane demo so it reads like an app-native messaging platform setup rather than a low-level transport sample.
Acceptance criteria