[FEAT] Implement Strict Payout Order Enforcement On-Chain

[Queenode]

🟡 Priority: High
Difficulty: Hard
Estimated Effort: 4-5 days
Relevant Files: contracts/src/lib.rs
Labels: enhancement, priority:high, logic

Requirements

1. Deterministic Rotations

   • Currently, payout(recipient) allows the admin to pick any member who hasn't received a payout. This allows the admin to play favorites.
   • Implement strict on-chain enforcement of the payout order based on join order (or a pre-defined array).

2. Payout Queue State

   • Replace the HasReceivedPayout boolean map with a NextPayoutIndex integer in instance storage (starting at 0).
   • The Members vector already establishes an order (index 0, index 1, etc.).

3. Enforce Queue

   • Modify payout() (or trigger_payout()) so it no longer takes a recipient argument.
   • Instead, it reads NextPayoutIndex.
   • recipient = members.get(NextPayoutIndex).
   • Execute the payout to that specific recipient.
   • Increment NextPayoutIndex by 1.

4. Cycle Boundaries

   • When NextPayoutIndex == Members.len(), the cycle is complete.
   • The reset_cycle() function should reset NextPayoutIndex to 0.
   • Ensure add_member and remove_member handle NextPayoutIndex gracefully (e.g., if a member is removed before their turn, shift the index or array).

5. Testing

   • Unit test: 3 members join. Payout 1 goes to member 0. Payout 2 goes to member 1.
   • Unit test: Attempt to bypass the queue (panics or automatically routes to the correct person).
   • Unit test: Cycle completes, resets, and starts again with member 0.
   • Target: 100% coverage on sequential payout logic.

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[OluRemiFour]

Hi Maintainer,
Interested in working on this issue. I'll implement the requested changes and ensure everything is properly tested before submission.

[Digitalasu]

Hi, I'd like to work on this issue. I've gone through the description and acceptance criteria and I'm confident I can deliver it. I'll make sure every acceptance criterion is met and submit a clean, tested PR. Please assign it to me.