[CO-02] Implement two-step admin transfer in loyalty_token to prevent irreversible lockout

[Leothosine]

Problem

contracts/loyalty_token/src/lib.rs:151-156 - transfer_admin() immediately overwrites the Admin storage key:

env.storage().instance().set(&DataKey::Admin, &new_admin);

A single typo in new_admin permanently locks out the current admin with no recovery path. No confirmation is required from the new admin, no event is emitted, and the ability to mint, burn, and manage the loyalty token contract is permanently lost.

Proposed Solution

Implement a two-step admin transfer:

1. transfer_admin(env, caller, new_admin) - sets DataKey::PendingAdmin, emits (symbol_short!("admin"), symbol_short!("proposed")). Does NOT change DataKey::Admin.
2. accept_admin(env, caller) - requires caller == PendingAdmin, promotes to Admin, clears PendingAdmin, emits accepted event
3. cancel_transfer(env, caller) - requires current admin auth, clears PendingAdmin

Acceptance Criteria

• Calling transfer_admin() alone does NOT change the active admin
• accept_admin() from any address other than PendingAdmin panics with "not pending admin"
• Happy path test: propose ? accept ? old admin can no longer mint
• Cancel test: propose ? cancel ? PendingAdmin cleared, old admin still active
• Both proposed and accepted events emitted at the correct step

[Menjay7]

Hi! I came across this issue and would love to work on it. I have experience with similar tasks and I'm confident I can investigate, implement a clean solution, and thoroughly test it before submitting a PR. If the issue is still open, I would appreciate it if you could assign it to me. Thank you!

[mftee]

Kindly assign me this issue. I can quickly resolve them and integrate it into existing systems. I am software developer with many years of experience.

[grantfox-oss]

🦊 GrantFox — @mftee 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 #280)
2. Your PR will be reviewed by the tosirano maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign campaign!

@mftee's PR #290 was approved and merged by @Leothosine.

🏆 @mftee: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (328 total points). Track your full progress on GrantFox.

👏 Great work, @mftee! Keep contributing to tosirano.