perf(streaming): scope reveal warmup spatially

Source composite warmup from the canonical published destination neighborhood, including quiesced static and live projections, instead of rescanning the retained Far-tier world after every membership edge.

This lifecycle correction applies to both draw paths, preserving ef1d263337 as the sole G4 visual rollback.

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

src/AcDream.App/Streaming/GpuWorldState.cs

@@ -449,6 +449,46 @@ public sealed class GpuWorldState : ILiveEntitySpatialQuery
         }
     }
 
+    /// <summary>
+    /// Copies every published projection from a bounded destination
+    /// neighborhood for presentation-readiness work. Unlike gameplay-facing
+    /// spatial queries, this remains available while the world generation is
+    /// quiesced: the reveal barrier must prepare destination resources before
+    /// it makes that generation observable.
+    /// </summary>
+    internal void CopyPublishedEntitiesNearLandblockForReadiness(
+        uint centerCellOrLandblockId,
+        int landblockRadius,
+        List<WorldEntity> destination)
+    {
+        ArgumentNullException.ThrowIfNull(destination);
+        ArgumentOutOfRangeException.ThrowIfNegative(landblockRadius);
+        destination.Clear();
+
+        int centerX = (int)((centerCellOrLandblockId >> 24) & 0xFFu);
+        int centerY = (int)((centerCellOrLandblockId >> 16) & 0xFFu);
+        for (int dx = -landblockRadius; dx <= landblockRadius; dx++)
+        for (int dy = -landblockRadius; dy <= landblockRadius; dy++)
+        {
+            int x = centerX + dx;
+            int y = centerY + dy;
+            if ((uint)x > 0xFFu || (uint)y > 0xFFu)
+                continue;
+
+            uint landblockId =
+                ((uint)x << 24) | ((uint)y << 16) | 0xFFFFu;
+            if (!_loaded.TryGetValue(
+                    landblockId,
+                    out LoadedLandblock? landblock))
+            {
+                continue;
+            }
+
+            for (int i = 0; i < landblock.Entities.Count; i++)
+                destination.Add(landblock.Entities[i]);
+        }
+    }
+
     public readonly ref struct MutationBatch
     {
         private readonly GpuWorldState _owner;