feat: increase verification signature max length (#2038)

## Motivation

Coinbase Smart Wallet signatures are 1088 bytes long. We've bumped this
several times, so add some headroom on top.

## Change Summary

Increase verification signature max length to 2048 bytes.

## Merge Checklist

_Choose all relevant options below by adding an `x` now or at any time
before submitting for review_

- [x] PR title adheres to the [conventional
commits](https://www.conventionalcommits.org/en/v1.0.0/) standard
- [x] PR has a
[changeset](https://github.com/farcasterxyz/hub-monorepo/blob/main/CONTRIBUTING.md#35-adding-changesets)
- [x] PR has been tagged with a change label(s) (i.e. documentation,
feature, bugfix, or chore)
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[documentation](https://github.com/farcasterxyz/hub-monorepo/blob/main/CONTRIBUTING.md#32-writing-docs)
if necessary.
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<!-- start pr-codex -->

---

## PR-Codex overview
This PR extends the maximum length of the `claimSignature` field in
verifications to 2048 bytes for better validation accuracy.

### Detailed summary
- Increased `claimSignature` max length from 512 to 2048 bytes in
validations
- Updated test cases to reflect the new max length of `claimSignature`

> ✨ Ask PR-Codex anything about this PR by commenting with `/codex {your
question}`

<!-- end pr-codex -->

.changeset/olive-readers-suffer.md

@@ -0,0 +1,5 @@
+---
+"@farcaster/core": patch
+---
+
+feat: extend verifications signature max length

packages/core/src/validations.test.ts

@@ -841,15 +841,15 @@ describe("validateVerificationAddEthAddressSignature", () => {
     expect(result).toEqual(err(new HubError("bad_request.invalid_param", "RPC client not provided for chainId 1")));
   });
 
-  test("fails if ethSignature is > 512 bytes", async () => {
+  test("fails if ethSignature is > 2048 bytes", async () => {
     const body = await Factories.VerificationAddAddressBody.create(
       {
-        claimSignature: Factories.Bytes.build({}, { transient: { length: 513 } }),
+        claimSignature: Factories.Bytes.build({}, { transient: { length: 2049 } }),
       },
       { transient: { protocol: Protocol.ETHEREUM } },
     );
     const result = await validations.validateVerificationAddEthAddressSignature(body, fid, network, {});
-    expect(result).toEqual(err(new HubError("bad_request.validation_failure", "claimSignature > 512 bytes")));
+    expect(result).toEqual(err(new HubError("bad_request.validation_failure", "claimSignature > 2048 bytes")));
   });
 
   test("succeeds for contract signatures", async () => {

packages/core/src/validations.ts

@@ -403,8 +403,8 @@ export const validateVerificationAddEthAddressSignature = async (
   network: protobufs.FarcasterNetwork,
   publicClients: PublicClients = defaultPublicClients,
 ): HubAsyncResult<Uint8Array> => {
-  if (body.claimSignature.length > 512) {
-    return err(new HubError("bad_request.validation_failure", "claimSignature > 512 bytes"));
+  if (body.claimSignature.length > 2048) {
+    return err(new HubError("bad_request.validation_failure", "claimSignature > 2048 bytes"));
   }
 
   const reconstructedClaim = makeVerificationAddressClaim(