fix(nft)!: align note-hashing with upstream aztec-nr scheme

[alejoamiras]

Part of a 4-PR all-or-nothing stack (#35 → #36 → #37 → #38). Drafts, proposed as one unit.

⚠️ BREAKING — changes NFT note hashes

A fixed contract deploys under a new class id. Existing on-chain NFTNotes were created under the old scheme and will not match. Practically:

• Drain or abandon in-flight partial notes before upgrading code at an existing address — the change also alters validity commitments, completion-log tags and commitment-storage keys, not just final note hashes.
• PXE/wallet note databases and clients must use the artifact matching each deployed class. Old instances remain valid with their old artifact.

What changed

nft_note.nr used a pre-refactor hashing scheme that diverged from upstream and from this repo's own multitoken_note.nr — two custom notes in one repo disagreeing for no reason:

	before	after (= upstream)
compute_partial_commitment	generic DOM_SEP__NOTE_HASH	dedicated DOM_SEP__PARTIAL_NOTE_COMMITMENT
compute_complete_note_hash	hand-rolled [commitment, storage_slot, token_id] (slot in the middle)	compute_note_hash(storage_slot, [commitment, token_id]) — the aztec-nr util, slot first

Both the direct note-hash path and the partial-note completion path route through these two functions, so directly-created and completed-partial notes stay indistinguishable. Ported upstream's note_hash_matches_completed_partial_note_hash test to lock that invariant, and corrected two comments that wrongly claimed the partial commitment includes the storage slot.

Validation

nft_contract 65 Noir tests · NFT TS integration 9/9 against a local sandbox — the load-bearing proof that PXE note discovery works under the new scheme · aztec compile OK.

Codex adversarial review: "matches upstream, correct, internally consistent."

[github-actions]

Benchmark Comparison

CPU	Cores	RAM	Arch
AMD EPYC 9V74 80-Core Processor	4	16 GiB	x64

Contract: escrow

🚦	Function	Gates			DA Gas			L2 Gas			Proving Time (ms)
		Base	PR	Diff	Base	PR	Diff	Base	PR	Diff	Base	PR	Diff
⚪	(partial) withdraw	485,780	485,780		3,744	3,744		587,800	587,800		14,023	11,666	-2,357 (-16.8%)
⚪	withdraw	330,054	330,054		832	832		499,700	499,700		11,274	9,536	-1,738 (-15.4%)
⚪	withdraw_nft	378,231	378,232	+1 (+0.0%)	1,440	1,440		527,400	527,400		12,389	10,434	-1,955 (-15.8%)

Contract: logic

🚦	Function	Gates			DA Gas			L2 Gas			Proving Time (ms)
		Base	PR	Diff	Base	PR	Diff	Base	PR	Diff	Base	PR	Diff
⚪	get_escrow	390,336	390,336		192	192		456,000	456,000		12,581	10,508	-2,073 (-16.5%)
⚪	secret_key_to_public_keys	387,695	387,695		192	192		456,000	456,000		12,616	10,577	-2,039 (-16.2%)
⚪	share_escrow	304,211	304,211		1,952	1,952		520,700	520,700		11,064	9,289	-1,775 (-16.0%)

Contract: multitoken

🚦	Function	Gates			DA Gas			L2 Gas			Proving Time (ms)
		Base	PR	Diff	Base	PR	Diff	Base	PR	Diff	Base	PR	Diff
⚪	burn_private	260,232	260,232		832	832		499,700	499,700		10,046	8,588	-1,458 (-14.5%)
⚪	burn_public	223,800	223,800		416	416		638,292	638,292		9,662	8,221	-1,441 (-14.9%)
⚪	initialize_transfer_commitment	225,054	225,054		768	768		474,500	474,500		9,644	8,244	-1,400 (-14.5%)
⚪	mint_to_private	297,795	297,795		1,408	1,408		511,400	511,400		10,974	9,257	-1,717 (-15.6%)
⚪	mint_to_public	223,800	223,800		416	416		637,800	637,800		9,721	8,200	-1,521 (-15.6%)
⚪	transfer_private_to_commitment	263,571	263,571		1,024	1,024		511,400	511,400		10,105	8,650	-1,455 (-14.4%)
⚪	transfer_private_to_private	336,124	336,124		2,048	2,048		555,100	555,100		11,445	9,646	-1,799 (-15.7%)
⚪	transfer_private_to_public	306,785	306,785		1,056	1,056		714,677	714,677		10,990	9,266	-1,724 (-15.7%)
⚪	transfer_public_to_commitment	223,800	223,800		640	640		663,516	663,516		9,709	8,222	-1,487 (-15.3%)
⚪	transfer_public_to_private	298,556	298,556		1,024	1,024		683,958	683,958		10,856	9,191	-1,665 (-15.3%)
⚪	transfer_public_to_public	223,800	223,800		480	480		673,505	673,505		9,663	8,245	-1,418 (-14.7%)

Contract: nft

🚦	Function	Gates			DA Gas			L2 Gas			Proving Time (ms)
		Base	PR	Diff	Base	PR	Diff	Base	PR	Diff	Base	PR	Diff
⚪	burn_private	275,232	275,233	+1 (+0.0%)	416	416		661,052	661,052		10,560	8,894	-1,666 (-15.8%)
⚪	burn_public	223,800	223,800		448	448		670,034	670,034		9,686	8,194	-1,492 (-15.4%)
⚪	mint_to_private	341,272	341,273	+1 (+0.0%)	1,600	1,600		735,342	735,342		11,406	9,701	-1,705 (-14.9%)
⚪	mint_to_public	223,800	223,800		448	448		670,718	670,718		9,638	8,189	-1,449 (-15.0%)
⚪	transfer_private_to_private	249,433	249,434	+1 (+0.0%)	832	832		499,700	499,700		9,959	8,394	-1,565 (-15.7%)
⚪	transfer_private_to_public	275,261	275,262	+1 (+0.0%)	416	416		659,258	659,258		10,582	8,912	-1,670 (-15.8%)
⚪	transfer_public_to_private	292,557	292,558	+1 (+0.0%)	992	992		683,268	683,268		10,728	9,137	-1,591 (-14.8%)
⚪	transfer_public_to_public	223,800	223,800		384	384		633,285	633,285		9,678	8,177	-1,501 (-15.5%)

Contract: token

🚦	Function	Gates			DA Gas			L2 Gas			Proving Time (ms)
		Base	PR	Diff	Base	PR	Diff	Base	PR	Diff	Base	PR	Diff
⚪	burn_private	303,054	303,054		1,024	1,024		713,957	713,957		10,931	9,257	-1,674 (-15.3%)
⚪	burn_public	223,800	223,800		448	448		672,632	672,632		9,648	8,164	-1,484 (-15.4%)
⚪	initialize_transfer_commitment	225,054	225,054		768	768		474,500	474,500		9,662	8,143	-1,519 (-15.7%)
⚪	mint_to_private	355,507	355,507		2,144	2,144		738,070	738,070		11,803	9,918	-1,885 (-16.0%)
⚪	mint_to_public	223,800	223,800		448	448		672,227	672,227		9,772	8,231	-1,541 (-15.8%)
⚪	transfer_private_to_commitment	259,896	259,896		992	992		511,400	511,400		10,107	8,522	-1,585 (-15.7%)
⚪	transfer_private_to_private	343,699	343,699		2,592	2,592		557,600	557,600		11,531	9,731	-1,800 (-15.6%)
⚪	transfer_private_to_public	303,110	303,110		1,024	1,024		714,023	714,023		11,004	9,214	-1,790 (-16.3%)
⚪	transfer_private_to_public_with_commitment	307,280	307,280		1,600	1,600		747,323	747,323		10,973	9,230	-1,743 (-15.9%)
⚪	transfer_public_to_commitment	223,800	223,800		576	576		662,529	662,529		9,625	8,216	-1,409 (-14.6%)
⚪	transfer_public_to_private	296,520	296,520		992	992		683,304	683,304		10,785	9,241	-1,544 (-14.3%)
⚪	transfer_public_to_public	223,800	223,800		448	448		672,548	672,548		9,706	8,183	-1,523 (-15.7%)

Contract: vault

🚦	Function	Gates			DA Gas			L2 Gas			Proving Time (ms)
		Base	PR	Diff	Base	PR	Diff	Base	PR	Diff	Base	PR	Diff
⚪	deposit_private_to_private	507,983	507,983		1,312	1,312		878,248	878,248		14,257	12,101	-2,156 (-15.1%)
⚪	deposit_private_to_private_exact	611,708	611,708		1,888	1,888		915,316	915,316		16,134	13,635	-2,499 (-15.5%)
⚪	deposit_private_to_public	435,487	435,487		768	768		862,273	862,273		13,184	11,096	-2,088 (-15.8%)
⚪	deposit_public_to_private	424,931	424,931		1,984	1,984		965,045	965,045		13,042	11,039	-2,003 (-15.4%)
⚪	deposit_public_to_private_exact	424,942	424,942		1,952	1,952		949,469	949,469		13,115	11,019	-2,096 (-16.0%)
⚪	deposit_public_to_public	223,800	223,800		832	832		897,563	897,563		9,641	8,213	-1,428 (-14.8%)
⚪	issue_private_to_private_exact	611,708	611,708		1,888	1,888		915,976	915,976		16,095	13,558	-2,537 (-15.8%)
⚪	issue_private_to_public_exact	484,222	484,222		1,344	1,344		899,998	899,998		13,791	11,948	-1,843 (-13.4%)
⚪	issue_public_to_private	346,383	346,383		1,376	1,376		921,661	921,661		11,563	9,774	-1,789 (-15.5%)
⚪	issue_public_to_public	223,800	223,800		832	832		898,253	898,253		9,697	8,246	-1,451 (-15.0%)
⚪	redeem_private_to_private_exact	614,712	614,712		1,888	1,888		915,823	915,823		16,059	13,598	-2,461 (-15.3%)
⚪	redeem_private_to_public	435,430	435,430		768	768		862,717	862,717		13,015	11,092	-1,923 (-14.8%)
⚪	redeem_public_to_private_exact	428,003	428,003		1,952	1,952		949,790	949,790		13,135	11,010	-2,125 (-16.2%)
⚪	redeem_public_to_public	223,800	223,800		832	832		898,085	898,085		9,652	8,252	-1,400 (-14.5%)
⚪	withdraw_private_to_private	510,987	510,987		1,312	1,312		878,458	878,458		14,131	12,028	-2,103 (-14.9%)
⚪	withdraw_private_to_private_exact	614,712	614,712		1,888	1,888		915,769	915,769		16,129	13,754	-2,375 (-14.7%)
⚪	withdraw_private_to_public_exact	484,165	484,165		1,344	1,344		900,232	900,232		13,865	11,774	-2,091 (-15.1%)
⚪	withdraw_public_to_private	441,260	441,260		2,528	2,528		967,356	967,356		13,197	11,219	-1,978 (-15.0%)
⚪	withdraw_public_to_public	223,800	223,800		832	832		898,388	898,388		9,727	8,203	-1,524 (-15.7%)