wip(step3): 12.5 cm voxels, fall-through fixed, brick evaluator in game, organic tunnels -- speed gate FAILS

Stopped by the owner's decision (in-game lit captures were eating the round); he judges the look in
game instead.
1. Fall-through with the research field: fixed. Deep drop, gate on: 2 holds (0.50 s), min foot
   clearance +43 cm; gate off: penetrates (-278 cm). Stress fixture offsets converted to metres.
2. VOXEL_SIZE 25 -> 12.5 cm. Physical sizes kept in metres (player, steps, gate, insets, research
   field sizes, dig radii, test thresholds); class defaults that count chunks/voxels doubled
   (ClipRadius 6, RenderDistanceChunks 1536, ViewDistance*, StrateViewMargin 6,
   PawnCollisionRadius 2, SkirtCells 4, EdgeSealThickness 128, decoration spacings, density volume
   res 256). Asset values override these defaults: the owner must double his own.
   Ring scale, six workers, idle, step-2f field before the look changes: 64 m cube (519^3) 4.55 s;
   32 m cube (259^3) 0.95 s.
3. In game: tiles go through the brick evaluator (proved by a log marker); profile switch rebuilds
   the loaded world (~5,800 tiles); full-detail fill 12.4 s after spawn in the visible-window test.
4. Look: round winding tunnels, per-column ellipsoid/lattice caches. All step-2f geometry gates pass
   at 12.5 cm (0 crumbs, 1 solid component per profile, solid share 69-87%). 259^3 ring, six workers:
   1.08-2.02 s (worst HyperComplex) -- the 600 ms gate FAILS. Lit captures failed (hidden/off-screen
   window, then blank frames); not pursued.

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

CLAUDE.md

@@ -25,7 +25,8 @@ try to run anything.
 ## Hard rules (these prevent real bugs — verify against code, don't assume)
 - **Density sign: negative = solid, positive = air** (MC convention at the mesher).
   `FVoxelModification::Strength` negative = carve. *The #1 source of confusion.*
-- **Density functions take VOXEL coords, not cm.** Conversions live in `VoxelTypes.h`.
+- **Density functions take VOXEL coords, not cm.** One voxel is 12.5 cm; one 32³ chunk is 4 m.
+  Conversions live in `VoxelTypes.h`.
 - **Determinism:** all randomness = hash of (coord, seed, strateIndex). No RNG state — same seed ⇒
   same world. Player edits (diff layer) are the only non-deterministic overlay.
 - **Async safety:** worker tasks only READ Generator/Mesher, must check `bShuttingDown`, and return via