fix(correctness): false AllAir certificates and a stale shaft cache key; 44/44 tests green

The harness's first full suite run showed 16 of 44 tests failing. Two were real defects in the owner's world:

1. ParameterRoll: the tile classifier could certify a box AllAir while the final field is solid there (3 false proofs found, e.g. density -2.092319 at (-192,16,-224)). Cause: the box diagnostic narrowed 'tail reach' to 'air reach', so the swept tunnel FLOOR -- which writes solid -- did not count as reaching the box. A false AllAir skips meshing, i.e. missing floor in game. The classifier now uses the same reach predicate as the final writer (swept chain, floor band, relief, room-mouth envelope) and propagates it through Mixed refinement nodes. Re-run: 1,288,143 lattice samples, 0 violations.

2. VerticalShaftEquivalence: LedgeSpacing and LedgeDepth were missing from the production TLS cache key, so a shaft could reuse stale ledge parameters. Both are now in the key.

The other 14: broken fixtures (missing staged corpus assets, a sampler leaking the shaft TLS marker between queries, stale candidate IDs, a window entirely inside the common tail) or stale expectations after this week's owner decisions (no authored tunnel floor, slope in degrees, rooms owning their interior). No test was deleted or weakened into vacuity; retired legacy comparisons stay as telemetry and the current stack is asserted instead. PassageLandsInOpenSpace now requires a real player-capsule fit in the final density at each authored landing (14/14, worst gradient 0.115723).

Suite: 42 tests green in one run, the two long op-stack sweeps green in serialized filtered runs (the 1800 s launch guard); a harness timeout-recording bug was fixed. Bounded probe exports unchanged (canonical 94B47A1C, owner 44E7C813). ⚠️ Harness perf scenario moved 50.74 s -> 53.58 s worker (+5.6%): the wider reach predicate skips fewer boxes. Measure on the game path and decide before merging.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MmSoF64BbRFmk9C3p1VsBJ

Source/VoxelForge/Private/VoxelDensityOpStack.cpp

@@ -2495,14 +2495,16 @@ namespace
             thread_local float   VS_Spacing = -1.0f, VS_Dens = -1.0f, VS_MinR = -1.0f,
                                  VS_MaxR = -1.0f, VS_Cross = -1.0f, VS_ConnR = -1.0f,
                                  VS_Rough = -1.0f, VS_SpineR = -1.0f,
-                                 VS_BotZ = FLT_MAX, VS_TopZ = FLT_MAX, VS_Seal = -1.0f;
+                                 VS_BotZ = FLT_MAX, VS_TopZ = FLT_MAX, VS_Seal = -1.0f,
+                                 VS_LedgeSpacing = -1.0f, VS_LedgeDepth = -1.0f;
 
             if (CX != VS_CX || CY != VS_CY || Salt != VS_Salt || Spacing != VS_Spacing ||
                 P.ShaftDensity != VS_Dens || P.ShaftMinRadius != VS_MinR || P.ShaftMaxRadius != VS_MaxR ||
                 P.CrossConnectChance != VS_Cross || P.ConnectorRadius != VS_ConnR ||
                 P.SurfaceRoughness != VS_Rough || SpineRadius != VS_SpineR ||
                 P.StrateBottomWorldZ != VS_BotZ || P.StrateTopWorldZ != VS_TopZ ||
-                P.BoundarySealThickness != VS_Seal)
+                P.BoundarySealThickness != VS_Seal || P.LedgeSpacing != VS_LedgeSpacing ||
+                P.LedgeDepth != VS_LedgeDepth)
             {
                 VS_CX = CX;  VS_CY = CY;  VS_Salt = Salt;  VS_Spacing = Spacing;
                 VS_Dens = P.ShaftDensity;  VS_MinR = P.ShaftMinRadius;  VS_MaxR = P.ShaftMaxRadius;
@@ -2510,6 +2512,7 @@ namespace
                 VS_Rough = P.SurfaceRoughness;    VS_SpineR = SpineRadius;
                 VS_BotZ = P.StrateBottomWorldZ;  VS_TopZ = P.StrateTopWorldZ;
                 VS_Seal = P.BoundarySealThickness;
+                VS_LedgeSpacing = P.LedgeSpacing; VS_LedgeDepth = P.LedgeDepth;
                 Cache.Shafts.Reset();
                 Cache.Conns.Reset();
 
@@ -6543,6 +6546,18 @@ namespace
                 CountThreshold(TunnelLowerNoWarp, B.HitTunnelsNoWarp);
             }
 
+            // The pointwise air probe above is intentionally narrower than the final generator
+            // tail: a tunnel can write a solid swept floor at lattice points where its core SDF
+            // is not negative.  Use the morphology module's shared broad reach predicate for the
+            // complete world-space core/floor envelope; it is the same bound used by the mesher's
+            // post-reach decision and keeps this diagnostic conservative for both polarities.
+            if (!B.bMayHaveTunnelCoreTail)
+            {
+                B.bMayHaveTunnelCoreTail =
+                    VoxelCaveMorphology::AnyTunnelCoreWorldNearLattice(
+                        GetBoxCache(), VoxelBox, 1.0f);
+            }
+
             if (B.bMayHaveTunnelCoreAir
                 && bUseLatticeProof
                 && ExactLatticeWorldQueries.Num() > 0)
@@ -6676,7 +6691,11 @@ namespace
                 {
                     B.bMayHaveTunnelCoreAir = bExactAir;
                     B.bMayHaveTunnelSupportFloor = false;
-                    B.bMayHaveTunnelCoreTail = bExactAir;
+                    // Keep the broad geometric tail candidate even when the exact lattice has
+                    // no core-air vertex.  The final generator tail writes both polarities:
+                    // it reopens tunnel air, but it can also write a solid swept floor below an
+                    // otherwise-air stack box.  Collapsing this flag to bExactAir erased the
+                    // latter reach and let the classifier certify a false AllAir child.
                 }
             }