Macro register 

macro_rules! register {
    ($name:literal, $func:path) => { ... };
}

Auto-register a sibling crate’s register fn into the global REGISTRARS slice.

Place at module scope inside the sibling crate, gated behind the crate’s registry cargo feature so the standalone build path stays decoupled from oxideav-core:

pub fn register(ctx: &mut oxideav_core::RuntimeContext) {
    /* install factories */
}

#[cfg(feature = "registry")]
oxideav_core::register!("aac", register);

The macro expands to a #[linkme::distributed_slice] static. The sibling crate must have linkme = "0.3" in its [dependencies] so the absolute path ::linkme::distributed_slice resolves at macro expansion time.