16. Add two-step admin transfer with optional delayed activation

[Cedarich]

Area: Soroban
Complexity: Medium

Summary:
Reduce operational risk by moving admin rotation away from single-step authority changes.

Acceptance Criteria:

• Pending admin nomination and acceptance exist.
• Optional delay or activation guard is supported cleanly.
• Unauthorized transitions fail predictably.

[Ayinkx]

Hi i would like to work on this issue please assign to me
I can do it perfectly

[paris27-A]

Hi! I’d like to take on this issue.

I’ll implement a secure two-step admin transfer flow by introducing pending admin nomination and explicit acceptance, with support for an optional activation delay/guard where appropriate. I’ll also ensure all unauthorized state transitions fail predictably, add comprehensive tests covering the new flow and edge cases, and keep the implementation consistent with the existing Soroban contract architecture.