Key protocol compatibility with BIP-032/Keycard

[jonesmarvin8]

🎯 Purpose

Fixes deviations from BIP-032 for compatibility with Keycard; addresses Issue 355.

⚙️ Approach

• Uses big endian for indices (public and private account keys for consistency)
• Non-harden keys (public account) uses full public key (33-bytes) for generation of children keys.
• Updated key tests

🧪 How to Test

RISC0_DEV_MODE=1 cargo test in key_protocol.

🔗 Dependencies

N/A

🔜 Future Work

N/A

📋 PR Completion Checklist

• Complete PR description
• Implement the core functionality
• Add/update tests
• Add/update documentation and inline comments

[Pravdyvy]

Looks fine for me, it changes accounts in wallet config, therefore need to change accounts in sequencer and indexer configs correspondingly to be in sync.

[Pravdyvy]

lgtm. I think latest main fixes this integration tests.