standalone: owner LOD0 defects -- relief blended as partition of unity (stairs gone), exposed skirts 0

- Stairs: cave, floor, strata and passage relief were effectively summed in overlaps (owner ray
  ~0.94 voxel of displacement); now partition-of-unity weights: -0.288 voxel there, max detail
  gradient 0.323 voxel/voxel. High-detail patch scan 133 -> 0; exact midpoint edge roots kept
  (removing them: 7,993 bad roots, 46 patches).
- Fins: exposed skirt triangle scan 1,776 -> 0; thin sheets 0; coarse off-surface panels 0.
- Path hash both directions equal; W1/W8 equal; routes 5642/5642; passage detail ratio 0.850;
  far survival passes, bad-shell fails; 30-crossing flight: nearest tile 15.1 ms median, 124 ms max.
Caveats seen in the captures: the owner-ray wall has visibly less relief than before; the fin
before/after captures do not show the fins (evidence is the scan only). Cold StreamFullClipmap
0.758 s vs 0.741 s (+17 ms, Luna's interleaved run). Owner to judge: bin\VoxelForgeLookCheck4.exe.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MmSoF64BbRFmk9C3p1VsBJ

Standalone/Source/StreamingWorld.h

@@ -483,6 +483,13 @@ public:
         return UpdateDesiredSet(std::move(NewDesired),ResidentKeys,CrossingIndex);
     }
 
+    FStandaloneStreamingUpdate UpdateDesiredWithSet(
+        FStandaloneDesiredTileSet NewDesired,const std::vector<FVoxelTileKey>& ResidentKeys,
+        uint64 CrossingIndex=0)
+    {
+        return UpdateDesiredSet(std::move(NewDesired),ResidentKeys,CrossingIndex);
+    }
+
     std::vector<FStandaloneCpuTile> TakeReady()
     {
         std::vector<FStandaloneCpuTile> Out;