- EnsureSentinel() maintains exactly one trailing empty plate, suppressing navigation events during mutation
- Reactive tail subscriptions (PartAdded/PartRemoved on last two plates) call EnsureSentinel automatically; re-subscribed after each plate list change
- BeginBatch()/EndBatch() defers sentinel enforcement during bulk operations
- GetOrCreateEmpty() returns or creates an empty plate; RemoveCurrent() removes the current plate with index clamping; CanRemoveCurrent guards deletion
- 13 new tests (30 total PlateManager tests), all passing
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
AJ Isaacs
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