refactor: replace queue mappings with sorted-array invariant (#116)

[RonTuretzky]

Summary

• Replace mapping-based O(1) duplicate detection with sorted-array invariant + O(log n) binary search
• Require ascending address order for queue submissions (QueueNotSorted error)
• Simplify clearAdditionQueue/clearRemovalQueue back to simple delete
• Keep MAX_QUEUE_SIZE = 100 cap from PR 1
• Add 6 new tests for sorted order, re-queue, and cross-queue independence

Revisits #45 (structural improvement over the mapping approach in PR 1)
Supersedes #116

Stack: PR 9 of 10 (0.0.2) — stacked on #125

[Copilot]

Pull request overview

Refactors recipient queue duplicate detection away from per-queue mappings into a sorted-address invariant, enabling cheaper queue clearing and O(log n) queued-membership checks via binary search across the queued arrays.

Changes:

• Introduces QueueNotSorted error and requires strictly ascending address order for queue submissions.
• Removes queue-membership mappings from storage usage; clearAdditionQueue/clearRemovalQueue revert to delete.
• Updates/extends tests to assert the new revert behavior and to cover re-queueing and cross-queue behavior.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
src/abstract/AbstractRecipientRegistry.sol	Enforces sorted-queue invariant, simplifies queue clearing, and implements binary search for isQueuedFor*.
src/interfaces/IRecipientRegistry.sol	Adds QueueNotSorted error and documents the new ordering requirement.
test/RecipientRegistry.t.sol	Updates expected revert selector for duplicate queueing to QueueNotSorted.
test/AdminRecipientRegistry.t.sol	Adds new tests for sorted order enforcement, re-queue after removal/clear, and cross-queue independence.

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[Copilot]

The QueueNotSorted NatSpec is inaccurate: the ascending-order invariant enables O(1) duplicate prevention at enqueue time (by comparing to the last element), while O(log n) applies to the isQueuedFor* lookup via binary search. Please update the comment to reflect the actual complexity/behavior so integrators don’t misunderstand the tradeoff.

Suggested change

	/// @dev Queues must be submitted in ascending address order to enable O(log n) duplicate detection
	/// @dev Queues must be submitted in strictly ascending address order so enqueue-time
	/// @dev duplicate/order validation can be done in O(1) by comparing against the last
	/// @dev queued element; the sorted invariant also enables O(log n) `isQueuedFor*`
	/// @dev lookups via binary search.

[Copilot]

RecipientAlreadyQueued remains in the interface, but no implementation appears to revert with it anymore (duplicate and out-of-order both revert QueueNotSorted). Either (a) reintroduce RecipientAlreadyQueued for the recipient == lastQueued case, or (b) explicitly deprecate/remove RecipientAlreadyQueued to avoid exposing an error that will never be thrown.

Suggested change

	/// @notice Thrown when attempting to queue a recipient that is already queued
	error RecipientAlreadyQueued();
	/// @notice Thrown when a recipient address is not greater than the last queued address
	/// @notice Thrown when a queued recipient address is not strictly greater than the last queued address
	/// @dev Covers both duplicate recipients and out-of-order queue submissions

[Copilot]

The enqueue path now enforces a strict ascending-address invariant (reverting QueueNotSorted when recipient <= lastQueued). Consider documenting this requirement in the function’s NatSpec (either here or on the external queueing functions) since it’s a behavioral/API constraint callers must follow.