Function run_steps_with_manager_with_modules 

pub fn run_steps_with_manager_with_modules<P>(
    fs: Box<dyn WorkspaceFs>,
    steps: &[Step],
    process: P,
    io: ExecIo,
    modules: Vec<HostModule<P>>,
    types: Vec<&'static TypeDescriptor>,
) -> Result<(GuardedPath, Box<dyn WorkspaceFs>, BTreeMap<String, Value>), Error>
where
    P: ProcessManager,

Same as run_steps_with_manager, plus host modules and types. Each module’s functions become callable as MODULE::NAME with full step context; each type descriptor becomes visible to TYPES() and valid for LET $x: NAME declarations carrying same-named opaque payloads. Authors should derive entries with #[oxdock_func] / #[oxdock_type] (see oxdock-func-macro) and group them into HostModule instead of hand-writing metadata and glue.