♻️ improve the creation signature

[qd-qd]

• Take into account the prefix used to identify the signature
• Rename loginHash to usernameHash
• Add the address of the account concerned by the signature in the signature
• Add the ID of the chain concerned by the creation of the account in the signature
• Remove the _checkAccountExistence function from the AccountFactory contract

[github-actions]

Changes to gas cost

Generated at commit: f72f4c9b0c3b42561514dcb84815a0f49519f958, compared to commit: d968577aad122f9a8ba0a481483f0fb6953e8646

🧾 Summary (20% most significant diffs)

Contract	Method	Avg (+/-)	%
AccountFactoryTestWrapper	isSignatureLegit	+25,119 ❌	+464.91%
WrapperAccount	validateCreationSignature	-3,499 ✅	-32.28%
ERC1967Proxy	validateCreationSignature	-3,499 ✅	-22.14%
MockFactory	mockDeployAccount	+22,194 ❌	+10.74%

---

Full diff report 👇

Contract	Deployment Cost (+/-)	Method	Min (+/-)	%	Avg (+/-)	%	Median (+/-)	%	Max (+/-)	%	# Calls (+/-)
AccountFactoryTestWrapper	2,503,254 (+29,439)	getAddress isSignatureLegit	4,411 (-45) 27,086 (+24,323)	-1.01% +880.31%	4,411 (-45) 30,522 (+25,119)	-1.01% +464.91%	4,411 (-45) 31,262 (+24,980)	-1.01% +397.64%	4,411 (-45) 31,514 (+25,196)	-1.01% +398.80%	3,074 (+3,073) 2,305 (+256)
WrapperAccount	0 (0)	validateCreationSignature	1,280 (0)	0.00%	7,341 (-3,499)	-32.28%	8,046 (-3,194)	-28.42%	10,805 (-10,355)	-48.94%	2,305 (-1)
ERC1967Proxy	146,238 (0)	validateCreationSignature	6,254 (0)	0.00%	12,304 (-3,499)	-22.14%	13,020 (-3,194)	-19.70%	15,779 (-10,355)	-39.62%	2,305 (-1)
MockFactory	3,305,548 (+172,453)	mockDeployAccount	228,751 (+22,194)	+10.74%	228,751 (+22,194)	+10.74%	228,751 (+22,194)	+10.74%	228,751 (+22,194)	+10.74%	10 (-1)
Signature_Test	1,987,710 (+195,888)	wrappedRecover	6,253 (-178)	-2.77%	6,253 (-178)	-2.77%	6,253 (-178)	-2.77%	6,253 (-178)	-2.77%	1 (0)
Account__ValidateCreationSignature	6,542,860 (+448,509)	_sliceBytes	1,072 (-22)	-2.01%	1,282 (-26)	-1.99%	1,300 (-22)	-1.66%	1,452 (-22)	-1.49%	256 (0)
AccountFactory	2,441,597 (+1,151)	createAndInitAccount	31,898 (-83)	-0.26%	177,801 (+79)	+0.04%	225,429 (+102)	+0.05%	225,429 (+102)	+0.05%	8 (0)
SignerVaultWebAuthnP256R1TestWrapper	645,931 (0)	remove set	29,760 (0) 29,486 (0)	0.00% 0.00%	29,964 (-7) 83,330 (-19)	-0.02% -0.02%	30,058 (0) 89,390 (-24)	0.00% -0.03%	30,058 (0) 89,930 (0)	0.00% 0.00%	256 (0) 2,304 (0)
Paymaster	968,289 (0)	deposit postOp	53,327 (+2,500) 22,249 (0)	+4.92% 0.00%	53,327 (+10) 22,844 (-1)	+0.02% -0.00%	53,327 (0) 22,441 (+6)	0.00% +0.03%	53,327 (0) 24,097 (0)	0.00% 0.00%	259 (0) 512 (0)
SignerVaultVanillaP256K1TestWrapper	239,984 (0)	remove set	22,344 (0) 44,268 (0)	0.00% 0.00%	22,506 (+2) 44,435 (+6)	+0.01% +0.01%	22,572 (0) 44,496 (0)	0.00% 0.00%	22,572 (0) 44,496 (0)	0.00% 0.00%	256 (0) 1,024 (0)
Account	1,548,870 (+6,499)	addFirstSigner	22,253 (0)	0.00%	59,375 (-1)	-0.00%	74,293 (0)	0.00%	94,937 (-12)	-0.01%	523 (0)
SmartAccountTestWrapper	1,563,433 (+6,691)
MockAccountFactory	3,890,941 (+113,356)
Account__validateWebAuthnP256R1Signature	4,975,787 (+117,006)

[qd-qd]

Slither sucks, we need to change.