refactor(runtime): own canonical action state

Move selection, combat, and interaction target mode under one Runtime owner; make plugins, retained UI, session routing, and typed runtime views borrow its exact children; and add failure-safe reset, instance isolation, source ownership, and normalized checkpoint coverage without changing retail ordering.

Co-authored-by: Codex <codex@openai.com>

tests/AcDream.App.Tests/UI/RetailUiInteractionFlowTests.cs

@@ -164,6 +164,7 @@ public sealed class RetailUiInteractionFlowTests
             var interaction = new ItemInteractionController(
                 Objects,
                 new InventoryTransactionState(Objects),
+                new InteractionState(),
                 playerGuid: () => Player,
                 sendUse: Uses.Add,
                 sendUseWithTarget: (source, target) => UseWithTarget.Add((source, target)),
@@ -199,6 +200,7 @@ public sealed class RetailUiInteractionFlowTests
             itemInteraction ??= new ItemInteractionController(
                 Objects,
                 new InventoryTransactionState(Objects),
+                new InteractionState(),
                 () => Player,
                 sendUse: null,
                 sendUseWithTarget: null,