State Transition

Explore animated transitions when data changes at runtime — actors entering, exiting, and moving between positions as filters are applied.

• SceneReconciler — pure diff engine that compares current scene against a new layout and produces a transition plan (enter/exit/move for actors, rugs, and flows)
• TransitionOrchestrator — phased animation sequencer that executes transition plans in 4 phases: EXIT → RUG RESHAPE → MOVE → ENTER, with staggered animations
• Transition scenarios — sequential filter snapshots simulating live data changes (progressive filter, scaling events, regrouping)
• useTransitionPlayer — composable wiring scenarios to reconciler + orchestrator with play/pause/step controls

New data (filtered actors + groupBy)
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LayoutEngine (unchanged, pure)
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SceneReconciler.diff() → TransitionPlan
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TransitionOrchestrator.execute(plan)
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Phased animations (EXIT 300ms → RUG 400ms → MOVE 500ms → ENTER 300ms)

• Incremental update over clear+redraw — filter changes typically add/remove a few actors, full rebuild would be jarring
• Reconciliation pattern — layout engine stays pure, diff logic is a separate layer
• Staggered animations — max 15 concurrent, 30ms stagger delay, capped per phase
• BaseMesh tweens reused for scale/opacity (battle-tested), animateValue() for position (new)

C11: Grid Layout — the layout engine, entity system, and composable architecture carry forward unchanged.