docs(comments): drop history narration, keep the why

Rewrite comments that told the story of past rounds instead of the
current code: dated "fixed on / tried on / reverted on" notes, "this used
to...", "stale paragraph removed", "Phase 1/2" progress labels, and the
"ClassifyTile still does not use ClassifyBox" claim (it does now, via
VF_ClassifyBoxWithWarpRetry). Every invariant, unit, sign convention,
trap and measurement that justified the design is kept, rephrased in the
present tense and in its original language (French or English).

Also fix comments that named symbols removed in the dead-code commit
(EvaluateSDF wrapper, FTunnelCoreWorldEvaluation support-floor fields,
BlendChunks -> TransitionBlendChunks) and the stale function name in the
VF_RollStrateParamsDetailed determinism checkf message.

Comment and message text only; no code token changed. Tests untouched.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01URDGLsu7c4nunqNFPJEFPU

Source/VoxelForge/Public/VoxelDensityPrimitives.h

@@ -68,8 +68,8 @@ FORCEINLINE void VF_ApplyBoundarySeal(float& Density, float WorldZ,
 // CARVE DE PASSAGE / PASSAGE CARVING
 //=============================================================================
 // Creuse un passage inter-strates. Évalué APRÈS le seal pour que les passages puissent percer à
-// travers le bouchon solide. Le rayon de blend hard-codé à 4.0f correspond à l'ancienne valeur —
-// à exposer via UVoxelSettings si on veut pouvoir le tweaker.
+// travers le bouchon solide. Le rayon de blend est hard-codé à 4.0f — à exposer via
+// UVoxelSettings si on veut pouvoir le tweaker.
 FORCEINLINE void VF_ApplyPassageCarving(float& Density, float ModSDF,
     float BaseDensity, float SealThickness)
 {