fix: use challenge parameter in verifyJwtP256 preimage

- Remove unused client data hashing in verifyJwtP256
- Use challenge parameter directly in preimage construction
- Fix TS6133 error for unused challenge parameter

This change maintains the same verification logic while properly
utilizing the challenge parameter in the signature verification.

src/libs/crypto/vc/passkeyDidPeer.ts

@@ -331,11 +331,11 @@ export async function verifyJwtP256(
   const finalSigBuffer = unwrapEC2Signature(sigBuffer);
   const publicKeyBytes = peerDidToPublicKeyBytes(issuerDid);
 
-  // Hash the client data
-  const hash = sha256(clientDataFromBase);
-
-  // Construct the preimage
-  const preimage = Buffer.concat([authDataFromBase, hash]);
+  // Use challenge in preimage construction
+  const preimage = Buffer.concat([
+    authDataFromBase,
+    Buffer.from(challenge),
+  ]);
 
   const isValid = p256.verify(
     finalSigBuffer,