fix: fixes #697

[ThomasPiellard]

Description

Fixes # 697

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I did not modify files generated from templates
• golangci-lint does not output errors locally
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[Copilot]

Pull Request Overview

This PR fixes issue #697 by updating the BlockSize computation and corresponding memory allocation to use a dynamic calculation based on the permutation parameters rather than a constant value.

• Updated the BlockSize method to return (h.params.Width / 2)*fr.Bytes across multiple permutation implementations.
• Revised the hash initialization functions to allocate byte slices using the computed block size.

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
field/koalabear/poseidon2/poseidon2.go	Updated BlockSize method to use h.params.Width / 2 * fr.Bytes
field/koalabear/poseidon2/hash.go	Updated Merkle Damgard hasher to use dynamic block size
field/goldilocks/poseidon2/poseidon2.go	Updated BlockSize method to use h.params.Width / 2 * fr.Bytes
field/goldilocks/poseidon2/hash.go	Revised hash initialization with dynamic block size allocation
field/generator/internal/templates/poseidon2/poseidon2.go.tmpl	Updated BlockSize method template to compute dynamic block size
field/generator/internal/templates/poseidon2/hash.go.tmpl	Updated template for hash initializer to use dynamic block size
field/babybear/poseidon2/poseidon2.go	Updated BlockSize method to compute dynamic block size
field/babybear/poseidon2/hash.go	Updated Merkle Damgard hasher to use dynamic block size allocation