feat/multisig-admin-controls

[Wetshakat]

closed #181

feat: Add multi-sig for critical admin actions

This pull request introduces a threshold-based multi-sig approval mechanism for critical administrative actions across all three pool
contracts (Rotational, Target, and Flexible). It also includes the corresponding frontend UI for managing multi-sig admins and
approving pending actions.

Smart Contract Changes

• Added a new Action enum to all three pool contracts to represent the different types of actions that can be approved.
• Added a new execute_approved function to all three pool contracts to execute actions approved by a multi-sig quorum.
• Modified the emergency_withdraw, pause, unpause, and remove_member functions to be callable only via execute_approved when a
  quorum is configured.
• Added view functions get_admin_quorum, get_pending_action, and get_approval_count to all three pool contracts.
• Added unit tests for the new multi-sig functionality.

Frontend Changes

• Created a new AdminQuorumManager component to manage the multi-sig quorum.
• Created a new PendingActionCard component to display pending actions.
• Added the AdminQuorumManager to the group detail page.
• Updated the existing admin action buttons to integrate with the new multi-sig flow.

Testing

• Unit tests were added for the new smart contract functionality.
• All tests for all three contracts are passing.

[Sendi0011]

Solid work on the multisig feature! The smart contract changes look well-structured. However, the frontend has several incomplete pieces that need to be addressed:

Critical:

1. pendingActions is always empty — fetchPendingActions is a stub that just does setPendingActions([]). The "Pending Actions" section will always show "No pending actions." Either implement the fetching or remove the section.

2. handleExecute is a no-op — In pending-action-card.tsx, the Execute button does nothing on click. Users can click it with zero feedback. Implement it or remove the button.

3. isApprovedByCurrentUser is never set to true — It's always false, so the Approve button always shows even if the user already approved.

Improvements:

4. action prop is typed as any — Define a proper interface: interface PendingAction { hash: string; type: string; requestedBy?: string; ... }.

5. Quorum threshold is derived as Math.ceil(quorumSize / 2) — This is a simple majority. Multisig systems should accept an explicit threshold parameter during set_admin_quorum. What happens with a 3-member quorum — is it 2-of-3 or 3-of-3?

6. No Stellar address validation — handleAddAdmin accepts any string. Validate the input is a valid Stellar public key before submitting to the contract.

7. group-actions.tsx calls getAdminQuorum directly — But you defined useGetAdminQuorum hook in the same PR. Use the hook for consistency.

8. 6 new test_snapshots/*.json files — If these are auto-generated snapshots, confirm they're intentional. Auto-generated snapshot files should be in .gitignore or generated in CI.