Feat/gpu prover

[zkfriendly]

Description

This PR introduces two main changes:

1. Adds GPU-based proof generation functionality through a new generate_proof_gpu function and keeps the generate_proof as is for backwards compatibility.
2. Adds a serde alias for pub_signals to support publicOutputs in JSON deserialization for gpu prover response.

Fixes # (issue)

Type of change

• 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

How Has This Been Tested?

• Tested GPU proof generation with valid input parameters
• Verified correct deserialization of proof responses with both pub_signals and publicOutputs fields

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[Bisht13]

Can you use #[serde(rename_all = "camelCase")] and change the field name accordingly?

[zkfriendly]

In the generate_proof function the modal API response is expected to include a snake case pub_signals, while the gpu prover API doesn't include a pub_signals or pubSignals, rather it has publicOutputs. Also rename_all doesn't seem to apply to alias names. So I'm not sure how I should use #[serde(rename_all = "camelCase")] and change the field name accordingly