fix(streaming): prepare quiesced destination entities

Separate loaded spatial residency from the world presentation gate so destination live objects acquire mesh owners behind portal space while drawing and simulation stay quiesced. Prevent unowned CPU-cache hits from recreating stale GPU staging work.

Co-authored-by: Erik Nilsson <erikn@users.noreply.github.com>

tests/AcDream.App.Tests/Streaming/GpuWorldStateVisibilityTests.cs

@@ -435,6 +435,43 @@ public sealed class GpuWorldStateVisibilityTests
         Assert.Equal(0, state.PendingVisibilityTransitionCount);
     }
 
+    [Fact]
+    public void QuiescedDestinationProjection_AcquiresSpatialPresentationBeforeWorldReveal()
+    {
+        const uint landblock = 0x0101FFFFu;
+        const uint cell = 0x01010001u;
+        const uint guid = 0x70000021u;
+        var availability = new WorldGenerationAvailabilityState();
+        availability.Begin(7);
+        var state = new GpuWorldState(availability: availability);
+        state.AddLandblock(new LoadedLandblock(
+            landblock,
+            new LandBlock(),
+            Array.Empty<WorldEntity>()));
+        var runtime = new LiveEntityRuntime(
+            state,
+            new DelegateLiveEntityResourceLifecycle(_ => { }, _ => { }));
+        WorldSession.EntitySpawn spawn = Spawn(guid, cell);
+        runtime.RegisterLiveEntity(spawn);
+        var edges = new List<bool>();
+        runtime.ProjectionVisibilityChanged += (_, visible) => edges.Add(visible);
+
+        runtime.MaterializeLiveEntity(
+            guid,
+            cell,
+            id => Entity(id, guid));
+
+        Assert.False(state.IsLiveEntityVisible(guid));
+        Assert.True(state.IsLiveEntityProjectionResident(guid));
+        Assert.True(runtime.TryGetRecord(guid, out LiveEntityRecord record));
+        Assert.True(record.IsSpatiallyVisible);
+        Assert.Equal([true], edges);
+
+        Assert.True(availability.End(7));
+        Assert.True(state.IsLiveEntityVisible(guid));
+        Assert.True(record.IsSpatiallyVisible);
+    }
+
     [Fact]
     public void CopyLiveEntitiesNearLandblock_UsesBoundedNeighborhoodAndSkipsStatics()
     {