wip(assembler): round S10 -- LOD8 horizon sampled at MC spacing: LOD8 worker time 18.8 s -> 4.3 s

Planar far horizon samples the LOD8 interior at the MC cell spacing, keeping
128-voxel boundary strips; far recipe v3. LOD8 p95 59.8 -> 13.9 ms, spawn
worker-seconds ~41 -> 26.9, full set 7.8 -> 7.1 s, ring 0.49 s, LOD0 1.43 s,
40 m/s ring 75/75. S3/S4 2 cm agreement, 100% cap coverage, W1/W8/W12 and
W1/W8/W16 determinism pass. Report: Standalone/Research/WorldAssemblerM3/Round14.

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

Tools/TestVoxelForgeCoreWorldHost.ps1

@@ -179,6 +179,7 @@ $RunName += switch ($NearReserveMode) {
     'Dynamic' { '_nearreserve_dynamic' }
     default { '_nearreserve_auto' }
 }
+if ($HybridFixturesOnly) { $RunName += "_$($CoreMesherRecipe.ToLowerInvariant())" }
 if ($EnforceCollisionGate) { $RunName += '_collision_gate' }
 if ($StartupTrace -or $StreamingTraceOnly) { $RunName += '_trace' }
 if ($StreamingTraceOnly) {