refactor(runtime): own magic and player state

Move the coupled Spellbook and LocalPlayerState into one Runtime-owned character graph, route content, live-session, retained UI, reset, and shutdown through that exact owner, and delete the duplicate desired-component snapshot from inventory state. Preserve synchronous retail update and reset ordering while adding independent-instance and retryable-failure coverage.

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

src/AcDream.App/Rendering/GameWindowLifetime.cs

@@ -85,6 +85,7 @@ internal sealed record LiveShutdownRoots(
     LiveEntityRuntime? LiveEntities,
     RuntimeEntityObjectLifetime EntityObjects,
     RuntimeInventoryState Inventory,
+    RuntimeCharacterState Character,
     RuntimeCommunicationState Communication,
     RenderSceneShadowRuntime? RenderSceneShadow,
     LivePresentationRuntimeBindings? PresentationBindings,
@@ -391,6 +392,9 @@ internal static class GameWindowShutdownManifest
             ]),
             new ResourceShutdownStage("runtime entity/object stream",
             [
+                Hard(
+                    "runtime character state",
+                    live.Character.Dispose),
                 Hard(
                     "runtime inventory state",
                     live.Inventory.Dispose),