fix(zktrie): add max recursion depth limit to countLeaves

[curryxbo]

Add maxZkTrieDepth (256) constant and depth check in countLeaves function to prevent potential stack overflow, node crashes, and DoS attacks.

The theoretical maximum depth of zkTrie is 256, so this limit ensures safe recursion while covering all valid use cases.

1. Purpose or design rationale of this PR

...

2. PR title

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• fix: A bug fix
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• test: Adding missing tests or correcting existing tests

3. Deployment tag versioning

Has the version in params/version.go been updated?

• This PR doesn't involve a new deployment, git tag, docker image tag, and it doesn't affect traces
• Yes

4. Breaking change label

Does this PR have the breaking-change label?

• This PR is not a breaking change
• Yes

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✨ Finishing touches

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