Service application facet

The service application facet is the runnable-process projection of a domain service: the application class, its host, the configuration options and parser, and the main() entry point that ores.codegen generates under --profile service. It turns a domain component into a deployable NATS service with consistent start-up, configuration and logging, so every service in the fleet is wired the same way.

The facet sits at the top of the entity lifecycle's service side. It emits the scaffolding a domain service needs to run:

• Application — the service class that owns the domain handlers and the NATS connection.
• Host — the process host that wires the application into the runtime (logging, lifecycle, signals).
• Configuration — the options struct and its command-line / file parser.
• Entry point — the main() that constructs and runs the host.

The business logic is hand-written; the facet generates the boilerplate around it. Read the template for the authoritative output rather than reproducing it here.

• Facet — the MASD facet concept this instantiates.
• Applied MASD — the full facet catalogue and codegen routes.
• cpp_service_app — the literate templates that generate this facet.
• Entity lifecycle — where the service facet sits in the layer ordering.