feat: implement permission system with operator management and tests

[ussyalfaks]

🚀 Implement Flexible Permission System for Tokenbound Accounts

close #6

📝 Description

This PR introduces a flexible permission system for tokenbound accounts, enabling:

• Granular access control via structured permissions
• Dynamic assignment & revocation of permissions
• Secure verification checks to restrict unauthorized actions
• Event emission for tracking permission changes

✅ Acceptance Criteria Met

Criteria	Status
Permission system functions correctly	✅
Permissions can be assigned & verified	✅
Unauthorized actions are blocked	✅
Authorized users can modify permissions	✅
Events emitted on permission changes	✅

🛠️ Changes Included

• Permission Struct: Defines permission levels & rules
• assign_permission(): Grants permissions to accounts
• check_permission(): Validates access before execution
• revoke_permission(): Removes permissions (admin-only)
• PermissionEvent: Logs changes (grant/revoke/modify)

🧪 Testing

1. Ran scarb build → success
2. Manual tests:
   • Assigned permissions → verified access
   • Attempted restricted actions → correctly blocked
   • Modified permissions → changes reflected & events emitted

📌 Notes

• Starred the repo ✅

[Pvsaint]

@ussyalfaks one of the check is failing after 9sec