chore: drop unused CodeRabbit config, ASCII-ify .nr comments

[alejoamiras]

Two hygiene items from the cleanup arc:

• .coderabbit.yaml deleted — CodeRabbit isn't enabled on this repo; the config is defi-wonderland fork inheritance with zero reviewer activity on any PR here.
• Six em-dashes in .nr sources replaced with ASCII (arc403_interface/src/main.nr, vault_contract/src/main.nr, two test files). These were latent versions of the bug that broke Noir Tests on docs: correct ARC-403 mint semantics and disclose known trust boundaries #24: nargo's auto-generated assert messages mix byte and char offsets when slicing source spans, so any multi-byte character above a bare assert in the same file shifts that assert's message by 2 chars and breaks exact-message tests (self.storage... → lf.storage...). All currently inert — this prevents the trap from ever firing. src is now verifiably pure ASCII.

Comment-and-string-only changes; no behavior, ABI, or gate-count impact expected (the two reworded TXE guard strings are referenced nowhere else).

🤖 Generated with Claude Code

[github-actions]

Benchmark Comparison

CPU	Cores	RAM	Arch
AMD EPYC 7763 64-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		13,838	13,757	-81 (-0.6%)
⚪	withdraw	330,054	330,054		832	832		499,700	499,700		11,178	11,148	-30 (-0.3%)
⚪	withdraw_nft	378,231	378,231		1,440	1,440		527,400	527,400		12,313	12,232	-81 (-0.7%)

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		12,439	12,424	-15 (-0.1%)
⚪	secret_key_to_public_keys	387,695	387,695		192	192		456,000	456,000		12,459	12,340	-119 (-1.0%)
⚪	share_escrow	304,211	304,211		1,952	1,952		520,700	520,700		10,952	10,938	-14 (-0.1%)

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		10,162	10,050	-112 (-1.1%)
⚪	burn_public	223,800	223,800		416	416		638,292	638,292		9,758	9,659	-99 (-1.0%)
⚪	initialize_transfer_commitment	225,054	225,054		768	768		474,500	474,500		9,690	9,589	-101 (-1.0%)
⚪	mint_to_private	297,795	297,795		1,408	1,408		511,400	511,400		10,932	10,819	-113 (-1.0%)
⚪	mint_to_public	223,800	223,800		416	416		637,800	637,800		9,657	9,639	-18 (-0.2%)
⚪	transfer_private_to_commitment	263,571	263,571		1,024	1,024		511,400	511,400		10,233	10,040	-193 (-1.9%)
⚪	transfer_private_to_private	336,124	336,124		2,048	2,048		555,100	555,100		11,350	11,339	-11 (-0.1%)
⚪	transfer_private_to_public	306,785	306,785		1,056	1,056		714,677	714,677		10,953	10,822	-131 (-1.2%)
⚪	transfer_public_to_commitment	223,800	223,800		640	640		663,516	663,516		9,772	9,705	-67 (-0.7%)
⚪	transfer_public_to_private	298,556	298,556		1,024	1,024		683,958	683,958		10,807	10,775	-32 (-0.3%)
⚪	transfer_public_to_public	223,800	223,800		480	480		673,505	673,505		9,690	9,600	-90 (-0.9%)

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	275,232		416	416		661,052	661,052		10,545	10,505	-40 (-0.4%)
⚪	burn_public	223,800	223,800		448	448		670,034	670,034		9,681	9,629	-52 (-0.5%)
⚪	mint_to_private	341,272	341,272		1,600	1,600		735,342	735,342		11,468	11,433	-35 (-0.3%)
⚪	mint_to_public	223,800	223,800		448	448		670,718	670,718		9,684	9,700	+16 (+0.2%)
⚪	transfer_private_to_private	249,433	249,433		832	832		499,700	499,700		9,934	9,939	+5 (+0.1%)
⚪	transfer_private_to_public	275,261	275,261		416	416		659,258	659,258		10,665	10,472	-193 (-1.8%)
⚪	transfer_public_to_private	292,557	292,557		992	992		683,268	683,268		10,774	10,715	-59 (-0.5%)
⚪	transfer_public_to_public	223,800	223,800		384	384		633,285	633,285		9,661	9,633	-28 (-0.3%)

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		10,915	10,851	-64 (-0.6%)
⚪	burn_public	223,800	223,800		448	448		672,632	672,632		9,641	9,642	+1 (+0.0%)
⚪	initialize_transfer_commitment	225,054	225,054		768	768		474,500	474,500		9,656	9,525	-131 (-1.4%)
⚪	mint_to_private	355,507	355,507		2,144	2,144		738,070	738,070		11,648	11,666	+18 (+0.2%)
⚪	mint_to_public	223,800	223,800		448	448		672,227	672,227		9,639	9,673	+34 (+0.4%)
⚪	transfer_private_to_commitment	259,896	259,896		992	992		511,400	511,400		10,090	10,037	-53 (-0.5%)
⚪	transfer_private_to_private	343,699	343,699		2,592	2,592		557,600	557,600		11,476	11,493	+17 (+0.1%)
⚪	transfer_private_to_public	303,110	303,110		1,024	1,024		714,023	714,023		10,803	10,817	+14 (+0.1%)
⚪	transfer_private_to_public_with_commitment	307,280	307,280		1,600	1,600		747,323	747,323		10,961	10,947	-14 (-0.1%)
⚪	transfer_public_to_commitment	223,800	223,800		576	576		662,529	662,529		9,696	9,698	+2 (+0.0%)
⚪	transfer_public_to_private	296,520	296,520		992	992		683,304	683,304		10,819	10,815	-4 (-0.0%)
⚪	transfer_public_to_public	223,800	223,800		448	448		672,548	672,548		9,621	9,722	+101 (+1.0%)

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		14,177	14,121	-56 (-0.4%)
⚪	deposit_private_to_private_exact	611,708	611,708		1,888	1,888		915,316	915,316		16,094	15,957	-137 (-0.9%)
⚪	deposit_private_to_public	435,487	435,487		768	768		862,273	862,273		13,152	13,019	-133 (-1.0%)
⚪	deposit_public_to_private	424,931	424,931		1,984	1,984		965,045	965,045		13,015	12,912	-103 (-0.8%)
⚪	deposit_public_to_private_exact	424,942	424,942		1,952	1,952		949,469	949,469		12,965	12,941	-24 (-0.2%)
⚪	deposit_public_to_public	223,800	223,800		832	832		897,563	897,563		9,783	9,647	-136 (-1.4%)
⚪	issue_private_to_private_exact	611,708	611,708		1,888	1,888		915,976	915,976		16,048	16,004	-44 (-0.3%)
⚪	issue_private_to_public_exact	484,222	484,222		1,344	1,344		899,998	899,998		13,959	13,803	-156 (-1.1%)
⚪	issue_public_to_private	346,383	346,383		1,376	1,376		921,661	921,661		11,569	11,471	-98 (-0.8%)
⚪	issue_public_to_public	223,800	223,800		832	832		898,253	898,253		9,819	9,658	-161 (-1.6%)
⚪	redeem_private_to_private_exact	614,712	614,712		1,888	1,888		915,823	915,823		16,111	15,983	-128 (-0.8%)
⚪	redeem_private_to_public	435,430	435,430		768	768		862,717	862,717		13,154	13,010	-144 (-1.1%)
⚪	redeem_public_to_private_exact	428,003	428,003		1,952	1,952		949,790	949,790		13,037	12,980	-57 (-0.4%)
⚪	redeem_public_to_public	223,800	223,800		832	832		898,085	898,085		9,707	9,586	-121 (-1.2%)
⚪	withdraw_private_to_private	510,987	510,987		1,312	1,312		878,458	878,458		14,232	14,093	-139 (-1.0%)
⚪	withdraw_private_to_private_exact	614,712	614,712		1,888	1,888		915,769	915,769		16,122	16,025	-97 (-0.6%)
⚪	withdraw_private_to_public_exact	484,165	484,165		1,344	1,344		900,232	900,232		13,983	13,829	-154 (-1.1%)
⚪	withdraw_public_to_private	441,260	441,260		2,528	2,528		967,356	967,356		13,216	13,124	-92 (-0.7%)
⚪	withdraw_public_to_public	223,800	223,800		832	832		898,388	898,388		9,743	9,568	-175 (-1.8%)