Function initialize_missing_app_runtime_state 

fn initialize_missing_app_runtime_state(
    app: &AppRuntime,
) -> Result<(), &'static str>

Initializes missing file-backed runtime state from an app-owned declarative seed.

This runs after configuration finalization so packaged, source, single-app, and shared-server loading all use the effective state path. Existing state is never overwritten, including when multiple loaders race to initialize the same app.