Function orchard_v6_verifier 

pub fn orchard_v6_verifier() -> &'static VerifierService

Returns the global Halo2 verifier for v6 Orchard-pool and Ironwood-pool bundles.

v6 Orchard and Ironwood bundles only exist from NU6.3 onward, so they always use the NU6.3 circuit — the same VERIFIER_NU6_3_ONWARD key that v5 Orchard bundles at NU6.3 route to.