standalone: far-survival audit + LOD8 default with explicit far shells; neighbourhood-first viewer

- FarSurvivalAudit: checks every stratum top/bottom boundary (4x4 columns per far tile) and every
  in-view far connector (sections <=128 voxels, 4 radial rays) against the emitted mesh. Falsified:
  removing one tile's shell triangles -> 16 missing, 16 holes, exit 14. Passes at LOD6/7/8.
- Far connectors follow source radial crossings; strata patches emitted at LOD7/8. Default LOD8.
- Viewer: separate near ShapeWorld for the 27 player tiles, full world built on its own thread;
  27/27 tiles hash-identical to the direct build. W1/W8 60 hash fields equal; routes 5642/5642.
Cost, measured by me head to head (8 workers, cold, BelowNormal 0xFF00): LOD8 without the shells
1.17-1.25 s, LOD8 with the shells 1.80 s; payload 92.6 -> 276.7 MiB. The shells are far too
expensive, and the pipelined benchmark whole view is 2.92 s (shape compiled twice): both to fix.

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

Standalone/Source/OwnerWorldLoader.h

@@ -30,7 +30,7 @@ struct FStandaloneOwnerWorld
     bool ViewerStartFound = false;
     int32 Seed = 0;
     int32 ClipRadius = 6;
-    int32 MaxClipLevel = 6;
+    int32 MaxClipLevel = 8;
     int32 FullResClipLevels = 2;
     int32 CoarseTileCells = 16;
     int32 RenderDistanceChunks = 1536;
@@ -253,7 +253,7 @@ namespace StandaloneOwnerLoader
         }
         Out.Seed = static_cast<int32>(Root.Get("seed").Integer());
         Out.ClipRadius = static_cast<int32>(Root.Get("clip_radius").Integer(6));
-        Out.MaxClipLevel = static_cast<int32>(Root.Get("max_clip_level").Integer(6));
+        Out.MaxClipLevel = static_cast<int32>(Root.Get("max_clip_level").Integer(8));
         Out.FullResClipLevels = static_cast<int32>(Root.Get("full_res_clip_levels").Integer(2));
         Out.CoarseTileCells = static_cast<int32>(Root.Get("coarse_tile_cells").Integer(16));
         Out.RenderDistanceChunks = static_cast<int32>(Root.Get("render_distance_chunks").Integer(1536));