Contract Admin Transfer with Two-Step Handover

[Kingsman-99]

Description

Directly setting a new admin address risks permanently locking the contract if the wrong address is provided. A two-step handover process — where the incoming admin must accept before the transfer completes — prevents accidental lockout.

Technical Context

Add pending_admin: Option<Address> to storage::instance in contracts/split/src/lib.rs. Add propose_admin_transfer(new_admin: Address) (current admin only) and accept_admin_transfer() (must be called by new_admin with require_auth). Only accept_admin_transfer writes the new admin as the active one. Emit AdminTransferProposed and AdminTransferCompleted from events.rs.

Acceptance Criteria

• propose_admin_transfer stores the pending admin and emits AdminTransferProposed
• Only the proposed address can call accept_admin_transfer
• The current admin remains active until accept_admin_transfer is called
• A pending transfer can be cancelled by the current admin calling cancel_admin_transfer
• AdminTransferCompleted(old_admin, new_admin) event is emitted on acceptance
• All CI checks (cargo build --target wasm32-unknown-unknown, cargo test, cargo clippy) pass and the branch has no merge conflicts

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[OgbuKingsley166]

@OgbuKingsley166 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

I’ve resolved similar problems in the past and am confident I can implement a clean, efficient fix quickly,if am given the opportunity.

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[Ahmedscreativeverse]

@Ahmedscreativeverse has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

I'd like to work on this issue. I've gone through the requirements carefully and have a solid understanding of the problem, expected behavior, implementation approach, and acceptance criteria. I already have a clear plan for delivering a clean, well-tested solution that aligns with the project's architecture. If assigned, I'll ensure the implementation is production-ready and meets all the stated requirements.

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[Danielobito009]

@Danielobito009 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hello maintainer!I would love to work on this issue,

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[probablyABug]

@probablyABug has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

hi, i would like to work on this.

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