feat(rendering): journal live scene projections

Mirror exact live-root and equipped-child lifetimes behind the non-drawing render-scene boundary. Ready, visibility, final-pose, rebucket, removal, and resource teardown edges retain canonical LiveEntityRuntime identity while active-only synchronization avoids resident-static scans.

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

tests/AcDream.App.Tests/World/LiveEntityHydrationControllerTests.cs

@@ -1,6 +1,7 @@
 using System.Numerics;
 using AcDream.App.Input;
 using AcDream.App.Rendering;
+using AcDream.App.Rendering.Scene;
 using AcDream.App.Streaming;
 using AcDream.App.World;
 using AcDream.Core.Items;
@@ -1496,6 +1497,63 @@ public sealed class LiveEntityHydrationControllerTests
         Assert.False(expected.IsSpatiallyProjected);
     }
 
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public void ReadyPublisher_PublishesRenderProjectionAfterExistingReadyStages(
+        bool projectionAccepted)
+    {
+        using var fixture = new Fixture(originKnown: true);
+        fixture.Controller.OnCreate(Spawn(Generation: 1, PositionSequence: 1));
+        LiveEntityRecord record = fixture.Record;
+        var operations = new List<string>();
+        var projection = new RecordingLiveProjectionSink(
+            _ =>
+            {
+                operations.Add("projection");
+                return projectionAccepted;
+            });
+        var publisher = new LiveEntityReadyPublisher(
+            fixture.Runtime,
+            _ => { operations.Add("effects-owner"); return true; },
+            _ => { operations.Add("state"); return true; },
+            _ => { operations.Add("effects-replay"); return true; },
+            projection);
+
+        bool result = publisher.Publish(
+            LiveEntityReadyCandidate.Capture(record));
+
+        Assert.Equal(projectionAccepted, result);
+        Assert.Equal(
+            ["effects-owner", "state", "effects-replay", "projection"],
+            operations);
+    }
+
+    [Fact]
+    public void ReadyPublisher_RevalidatesAfterReentrantRenderProjectionCallback()
+    {
+        using var fixture = new Fixture(originKnown: true);
+        fixture.Controller.OnCreate(Spawn(Generation: 1, PositionSequence: 1));
+        LiveEntityReadyCandidate candidate =
+            LiveEntityReadyCandidate.Capture(fixture.Record);
+        var projection = new RecordingLiveProjectionSink(
+            _ =>
+            {
+                fixture.Runtime.RegisterLiveEntity(
+                    Spawn(Generation: 1, PositionSequence: 2));
+                return true;
+            });
+        var publisher = new LiveEntityReadyPublisher(
+            fixture.Runtime,
+            static _ => true,
+            static _ => true,
+            static _ => true,
+            projection);
+
+        Assert.False(publisher.Publish(candidate));
+        Assert.Equal(2UL, fixture.Record.CreateIntegrationVersion);
+    }
+
     [Fact]
     public void EquippedChildReadyCandidate_RejectsVersionAdvancedByPoseCallback()
     {
@@ -1937,6 +1995,36 @@ public sealed class LiveEntityHydrationControllerTests
         }
     }
 
+    private sealed class RecordingLiveProjectionSink(
+        Func<LiveEntityReadyCandidate, bool> ready)
+        : ILiveRenderProjectionSink
+    {
+        public bool OnEntityReady(LiveEntityReadyCandidate candidate) =>
+            ready(candidate);
+
+        public void OnProjectionVisibilityChanged(
+            LiveEntityRecord record,
+            bool visible)
+        {
+        }
+
+        public void OnProjectionPoseReady(uint serverGuid)
+        {
+        }
+
+        public void OnProjectionRemoved(uint localEntityId)
+        {
+        }
+
+        public void OnResourceUnregister(WorldEntity entity)
+        {
+        }
+
+        public void SynchronizeActiveSources()
+        {
+        }
+    }
+
     private sealed class RecordingOrigin(bool isKnown) : ILiveEntityWorldOriginCoordinator
     {
         public bool IsKnownValue { get; set; } = isKnown;