Function run_dev_application 

pub fn run_dev_application(
    config: FrameConfig,
    spec: AppSpec,
    page: PageServer,
    dev: DevWiring,
) -> Result<(), HostError>

run_application, started in DEV mode (F-7b): identical boot and serve, plus the management door — the conversation is opened on the embedded bus, the handoff line is printed on stdout, and the adapter thread serves stage-and-activate requests behind the crate::dev::require_dev_node gate. A dev-client disconnect is an owner-defined stop: the serve future resolves and the ordinary ordered teardown runs — never scheduler-shutdown-as-cleanup.

Errors

Returns the first typed failure from boot, the door open, serving, or ordered shutdown.