Function spec_from_wit 

pub fn spec_from_wit(
    wit: TransientSpec,
    registry: &CommandRegistryHandle,
    plugin: &str,
) -> TransientSpec

Convert a guest-built spec into the native one, resolving each action row’s command name against registry.

Never fails: a row the host cannot honour is dropped, not escalated. The only way a plugin loses its whole menu is by returning an err from build, which is a statement rather than an accident.