Function build_shield_from_asset_lock_transition 

pub fn build_shield_from_asset_lock_transition<P: OrchardProver>(
    recipient: &OrchardAddress,
    shield_amount: u64,
    asset_lock_proof: AssetLockProof,
    asset_lock_private_key: &[u8],
    prover: &P,
    memo: [u8; 36],
    sender_ovk: Option<OutgoingViewingKey>,
    surplus_output: Option<PlatformAddress>,
    dummy_outputs: usize,
    platform_version: &PlatformVersion,
) -> Result<StateTransition, ProtocolError>

Builds a ShieldFromAssetLock state transition (core asset lock -> shielded pool).

Like Shield, constructs an output-only Orchard bundle. The funds come from a core asset lock proof rather than platform address inputs.

Parameters

• recipient - Orchard address to receive the shielded note
• shield_amount - Amount of credits to shield (from the asset lock)
• asset_lock_proof - Proof that funds are locked on core chain
• asset_lock_private_key - Private key for the asset lock (signs the transition)
• prover - Orchard prover (holds the Halo 2 proving key)
• memo - 36-byte structured memo for the recipient (4-byte type tag + 32-byte payload)
• sender_ovk - The sender’s outgoing viewing key (External scope). With Some, the recipient output’s out_ciphertext is encrypted under it so the sender can later recover the sent note (recipient, value, memo) from chain data via OVK recovery — the Zcash outgoing-transaction-history convention. With None, a random outgoing cipher key is used and the sent note is unrecoverable by anyone.
• surplus_output - Optional platform address that receives the asset-lock surplus (asset_lock_value − shield_amount − fee); when None, the surplus is added to the fee pools, capped at shielded_implicit_fee_cap
• dummy_outputs - Number of extra zero-value anonymity-set filler outputs to append after the real recipient output (unrecoverable random addresses, None OVK, empty memo). 0 reproduces the historical single-output bundle exactly. The on-wire action count becomes max(1 + dummy_outputs, 2), which consensus prices the fee from — see the pool-seeding flow.
• platform_version - Protocol version