refactor(world): extract live appearance and parenting

Move ObjDesc, Parent, Pickup, child-ready, and retained projection recovery into LiveEntityHydrationController while preserving retail timestamp and leave-world semantics. Pin ready publication to exact projection authority and restore attached descendant chains synchronously.

tests/AcDream.App.Tests/Rendering/EquippedChildProjectionWithdrawalTests.cs

@@ -433,6 +433,134 @@ public sealed class EquippedChildProjectionWithdrawalTests
         Assert.Equal(LiveEntityProjectionKind.Attached, child.ProjectionKind);
     }
 
+    [Fact]
+    public void SpawnParentWithoutAnimationFrame_UsesRetailPlacementZero()
+    {
+        using var fixture = new ControllerFixture((_, _, _) =>
+            new ExactProjectionWithdrawalOutcome(
+                ExactProjectionWithdrawalDisposition.Completed,
+                Failure: null));
+        LiveEntityRecord parent = fixture.Spawn(0x70000270u, generation: 1);
+        WorldSession.EntitySpawn childSpawn = ControllerFixture.SpawnData(
+            0x70000271u,
+            generation: 1) with
+        {
+            Position = null,
+            ParentGuid = parent.ServerGuid,
+            ParentLocation = 0,
+            PlacementId = null,
+            PositionSequence = 0,
+        };
+        LiveEntityRecord child = fixture.Live.RegisterLiveEntity(childSpawn).Record!;
+
+        fixture.Controller.OnSpawn(childSpawn);
+
+        var expected = new ParentAttachmentRelation(
+            parent.ServerGuid,
+            child.ServerGuid,
+            ParentLocation: 0,
+            PlacementId: 0,
+            ParentInstanceSequence: 0,
+            ChildPositionSequence: 0);
+        Assert.True(fixture.Live.ParentAttachments.IsCommitted(expected));
+        fixture.Poses.Publish(parent.WorldEntity!, Array.Empty<Matrix4x4>());
+        fixture.Controller.OnPosePublished(parent.ServerGuid);
+        Assert.Equal(LiveEntityProjectionKind.Attached, child.ProjectionKind);
+        Assert.NotNull(child.WorldEntity);
+    }
+
+    [Fact]
+    public void ObjDesc_ReprojectsAttachedChildWithoutWorldPositionOrIdentityChange()
+    {
+        ControllerFixture? fixture = null;
+        fixture = new ControllerFixture((record, positionVersion, projectionVersion) =>
+        {
+            bool completed = fixture!.Live.WithdrawLiveEntityProjection(
+                record,
+                positionVersion,
+                projectionVersion);
+            return new(
+                completed
+                    ? ExactProjectionWithdrawalDisposition.Completed
+                    : ExactProjectionWithdrawalDisposition.Superseded,
+                Failure: null);
+        });
+        using (fixture)
+        {
+            LiveEntityRecord parent = fixture.Spawn(0x70000272u, generation: 1);
+            WorldSession.EntitySpawn childSpawn = ControllerFixture.SpawnData(
+                0x70000273u,
+                generation: 1) with
+            {
+                Position = null,
+                ParentGuid = parent.ServerGuid,
+                ParentLocation = 0,
+                PlacementId = 0,
+                PositionSequence = 0,
+            };
+            LiveEntityRecord child = fixture.Live.RegisterLiveEntity(childSpawn).Record!;
+            fixture.Controller.OnSpawn(childSpawn);
+            fixture.Poses.Publish(parent.WorldEntity!, Array.Empty<Matrix4x4>());
+            fixture.Controller.OnPosePublished(parent.ServerGuid);
+            WorldEntity entity = child.WorldEntity!;
+            Assert.Null(entity.PaletteOverride);
+            WorldSession.EntitySpawn grandchildSpawn = ControllerFixture.SpawnData(
+                0x70000274u,
+                generation: 1) with
+            {
+                Position = null,
+                ParentGuid = child.ServerGuid,
+                ParentLocation = 0,
+                PlacementId = 0,
+                PositionSequence = 0,
+            };
+            LiveEntityRecord grandchild = fixture.Live.RegisterLiveEntity(
+                grandchildSpawn).Record!;
+            fixture.Controller.OnSpawn(grandchildSpawn);
+            WorldEntity grandchildEntity = grandchild.WorldEntity!;
+            Assert.Equal(
+                LiveEntityProjectionKind.Attached,
+                grandchild.ProjectionKind);
+
+            Assert.True(fixture.Live.TryApplyObjDesc(
+                new ObjDescEvent.Parsed(
+                    child.ServerGuid,
+                    new CreateObject.ModelData(
+                        BasePaletteId: 0x04000022u,
+                        [new CreateObject.SubPaletteSwap(
+                            0x0F000033u,
+                            Offset: 4,
+                            Length: 8)],
+                        Array.Empty<CreateObject.TextureChange>(),
+                        Array.Empty<CreateObject.AnimPartChange>()),
+                    InstanceSequence: 1,
+                    ObjDescSequence: 1),
+                out _));
+            Assert.Null(child.Snapshot.Position);
+
+            Assert.True(fixture.Controller.TryApplyAttachedAppearance(
+                child,
+                child.ObjDescAuthorityVersion));
+
+            Assert.Same(entity, child.WorldEntity);
+            Assert.True(child.IsSpatiallyProjected);
+            Assert.Equal(LiveEntityProjectionKind.Attached, child.ProjectionKind);
+            Assert.Equal((uint)0x04000022u, child.Snapshot.BasePaletteId);
+            Assert.NotNull(entity.PaletteOverride);
+            Assert.Equal(0x04000022u, entity.PaletteOverride!.BasePaletteId);
+            PaletteOverride.SubPaletteRange range =
+                Assert.Single(entity.PaletteOverride.SubPalettes);
+            Assert.Equal(0x0F000033u, range.SubPaletteId);
+            Assert.Equal((byte)4, range.Offset);
+            Assert.Equal((byte)8, range.Length);
+            Assert.Same(grandchildEntity, grandchild.WorldEntity);
+            Assert.True(grandchild.IsSpatiallyProjected);
+            Assert.Equal(
+                LiveEntityProjectionKind.Attached,
+                grandchild.ProjectionKind);
+        }
+    }
+
     [Fact]
     public void ChildWithoutSetup_StillCommitsLogicalParenting()
     {