Function verify_orchard_bundle 

fn verify_orchard_bundle(
    bundle: Option<Bundle<Authorized, ZatBalance>>,
    sighash: &SigHash,
    network_upgrade: NetworkUpgrade,
) -> AsyncChecks

Verifies a v5 transaction’s Orchard bundle.

A v5 Orchard bundle commits to the Orchard Action circuit of the block’s era, so the verifying key is selected by network_upgrade via primitives::halo2::orchard_v5_verifier_for: the historical insecure key before NU6.2, the fixed key from NU6.2 until NU6.3, and the NU6.3 key from NU6.3 onward. The Orchard-pool cross-address restriction applies to every Orchard Action from NU6.3 onward regardless of transaction version (ZIP 229), so a v5 bundle at NU6.3 uses the NU6.3 circuit — the same key as v6 Orchard and Ironwood bundles — not the fixed one.