[Medium] Implement Health Authority contract

[Josie123-Dev]

Task Description

Create Health Authority contract:

• Register health authorities
• Store authority public keys
• Validate authority signatures
• Manage authority status
• Implement authority verification

Requirements

• Authority registration
• Key storage
• Signature validation
• Status management
• Authority verification

Acceptance Criteria

• Registration works
• Keys are stored
• Signatures are validated
• Status is managed
• Verification works

[Arowolokehinde]

can i work on this issue? i have the neccessary expertise needed to work on this issue. i am a software developer with solid exprience in writing rust and typescript programs and working on this issue would give me more exposure to your codebase . i hope to learn more while contributing

[CeceOs92]

I can implement this contract if assigned.

[grantfox-oss]

🦊 GrantFox — @CeceOs92 has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #89)
2. Your PR will be reviewed by the GuardZero144 maintainers

Good luck! Track your progress on GrantFox.