checkpoint: preserve user-gated FW closeout fixes

src/AcDream.Core/Physics/ShadowObjectRegistry.cs

@@ -2146,6 +2146,22 @@ public sealed class ShadowObjectRegistry
         return System.Array.Empty<ShadowEntry>();
     }
 
+    /// <summary>
+    /// The exact ordered <c>CELLARRAY</c> membership retained for one physics
+    /// object. Retail consumes this same membership twice: collision walks
+    /// each cell's <c>shadow_object_list</c>, while rendering installs the
+    /// object's parts in every member cell through
+    /// <c>CPhysicsObj::add_shadows_to_cells</c> / <c>CPartArray::AddPartsShadow</c>
+    /// (0x00514AE0). The returned view is borrowed and remains valid only
+    /// until the next shadow-registry mutation.
+    /// </summary>
+    public IReadOnlyList<uint> GetOwnerCells(uint entityId)
+    {
+        if (_entityToCells.TryGetValue(entityId, out List<uint>? cells))
+            return cells;
+        return System.Array.Empty<uint>();
+    }
+
     public int TotalRegistered => _entityToCells.Count;
 
     /// <summary>