fix: include aa_authorization_list in the 0x76/0x78 signing-hash preimages

[compusophy]

Problem

On protocol/transactions/spec-tempo-transaction, the Signing Domains field lists disagree with the node's actual encoder:

1. Fee Payer Signature Hash (keccak256(0x78 || rlp([...]))) jumps from sender_address straight to key_authorization, omitting aa_authorization_list (and is missing the comma after sender_address).
2. Both Sender Signature Hash blocks (keccak256(0x76 || rlp([...]))) end at the field-12 fee-payer placeholder, omitting aa_authorization_list and the optional key_authorization (true positions 13 and 14).

The RLP Encoding section further down the same page already lists the envelope correctly (... fee_payer_signature, aa_authorization_list, key_authorization?, sender_signature) — only the signing-hash blocks are stale. An implementor who follows them verbatim produces signatures the chain rejects whenever they trust the spec over the reference client.

Ground truth

Node source — tempoxyz/tempo crates/primitives/src/transaction/tempo_transaction.rs: both signature_hash() (via encode_for_signing) and fee_payer_signature_hash() route through the shared rlp_encode_fields helper, which unconditionally encodes the authorization list and the optional key authorization after the fee-payer-signature slot:

encode_signature(&self.fee_payer_signature, out);

// Encode authorization_list
self.tempo_authorization_list.encode(out);

// Encode key_authorization (truly optional - only encoded if present)
if let Some(key_auth) = &self.key_authorization {
    key_auth.encode(out);
}

For the fee-payer domain, fee_payer_signature_hash(sender) passes a closure that encodes sender in that slot — the trailing fields are identical.

wevm/ox — src/tempo/TxEnvelopeTempo.ts uses one field list for both domains; deserialize destructures ..., feePayerSignatureOrSender, authorizationList, keyAuthorizationOrSignature, ... in exactly this order.

Live verification — the localharness Rust implementation (an independent 0x76 encoder, not derived from alloy or ox) only produced signatures accepted by both Moderato and Tempo mainnet once aa_authorization_list was included in both preimages; following this page as written yields invalid-signature rejections.

Fix

Minimal edit to the three signing-hash code blocks: append aa_authorization_list and key_authorization? (comment style copied from the page's own RLP Encoding block), and add the missing comma after sender_address. Nothing else touched.

A mirror PR against the canonical TIP (tempoxyz/tempo tips/tip-0001.md, which this page tracks) is being filed simultaneously. Precedent for clarifying this section: #111.

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[compusophy]

Companion PR for the canonical TIP: tempoxyz/tempo#6842