Build Deduplication Queue Screen

Use a BlocBuilder consuming DeduplicationQueueBLoC state (loading, loaded, error) to drive the screen. The queue list should use AnimatedList (not ListView) so item removals animate smoothly. For real-time updates, the DeduplicationQueueService streams queue changes — have the BLoC subscribe to the stream and emit DeduplicationQueueUpdated events. The 'Select All' visibility threshold of 3+ items reflects NHF's group event use case where bulk registration creates many duplicates simultaneously — below 3, per-item resolution is less disruptive.

Use a SliverList inside a CustomScrollView for the queue to allow a sticky bulk-action bar at the bottom. The BulkDismissConfirmationDialog should be a simple AlertDialog with item count and 'Dismiss N items' / 'Cancel' buttons — no need for a custom bottom sheet. For the expanded DuplicateComparisonPanel, use a single-expansion model: store the expanded item ID in BLoC state, not local widget state, so it survives rebuilds.

Widget tests: verify empty state renders when queue is empty. Verify loading skeleton shown during initial fetch. Verify 'Select All' checkbox appears only when 3+ items present. Verify bulk dismiss confirmation dialog shows correct item count.

Verify individual item resolve removes it from AnimatedList. Verify role guard redirects peer mentor users. BLoC integration tests: verify real-time removal when another coordinator resolves an item. Verify bulk dismiss emits correct events and all items are removed on success.

Accessibility tests: verify each queue item tile has correct Semantics label including peer mentor name and conflict type. Golden test: render queue with 3 items at standard and large font sizes.