Add Admin Key Rotation Function

[Just-Bamford]

��# Issue 7: Add Admin Key Rotation Function

Problem

Admin key is locked after initialization. No way to rotate compromised keys or transfer admin rights.

Solution

• Implement rotate_admin(new_admin: Address) function (lib.rs)
• Only current admin can call it; validates new admin isn't zero address or same as current
• Emits rotation event with old/new admin for audit trail
• TypeScript helper sorobanRotateAdmin() to invoke from core

Implementation Tasks

• Add rotate_admin() function in lib.rs with auth guard
• Emit ("admin", "rotated") event with timestamps
• Store rotation history in contract state
• Add sorobanRotateAdmin() TypeScript helper
• Unit tests: old admin locked out, new admin has privileges
• Integration test: full rotation flow works end-to-end

Note for Contributors

This issue is independent but should be completed after Issue #1 if metadata storage is enhanced. The rotation is immediate (not time-locked) for MVP simplicity. Store full rotation history in events; external systems will reconstruct admin ownership from the event stream. Use env.ledger().timestamp() for rotation timestamps. Ensure old admin loses all privileges immediately after rotation completes. Test both successful rotations and rejection of invalid rotations (zero address, same admin).

[Venrable18]

Good day maintainer..

I’m a full-stack and test integration developer…. 

Please assign this task to me…

[Hahfyeex]

Hi maintainer, I would like to work on this issue, will be able to tackle this issue and send a PR in the next 24 hrs

[grantfox-oss]

🦊 GrantFox — @Hahfyeex 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 #25)
2. Your PR will be reviewed by the AnonVote maintainers

Good luck! Track your progress on GrantFox.