skip: passage proof bounds include wall/floor relief (L75 soundness fix); FI -7.6%

L74's passage bound omitted the 0.21 m wall relief and 0.20 m floor relief, so its whole-tile
proof was unsound in principle (no tested view hit it). Passage support is now bounded per route
segment by four parameter-subinterval boxes using Catmull-Rom derivative extrema, local max
radius and relief padding. Stratum slicing only at LOD0-2 in FI/VS. Legacy sub-tile block
certificates are audit-only (runtime version was slower). TN regression (-80,-20,-3218) kept.

Exact full-grid vs skip hashes on every tile, 4 views, Clang/GCC, W1/W8/W12; control caught;
80-camera sweep 0 violations. Whole view vs c67b200: SW -1.3%, FI -7.6%, TN -2.3%, VS +0.2%.
Compiles in the Linux UE host (VFHostEditor, 27/27 actions).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016dhxM43dnWvUu2B5Ph1iG1

Standalone/Tools/verify/baselines/owner-hash/canonical/owner-hash-floating-islands-style2-l75-fullgrid.baseline

@@ -0,0 +1,12 @@
+[PipelineFullDetailHash] tiles=960 density=0x151044001ea90cd5 mesh=0xa818654be89790ac payload=0x370ff80451105a39 topology=0x06e507557aa70173
+[PipelineWholeViewHash] tiles=2370 density=0xf7bb51a4667eac72 mesh=0x937b616fe3c0bdc2 payload=0x230c904a12575f05 topology=0x6284613657ddb7fe
+[PipelineLODHash] lod=0 tiles=512 density=0x2fd4c78685a43cfe mesh=0x50478cff1c1f8ca0 payload=0x54e48e57e0af26de topology=0x860c011cfdb9833a
+[PipelineLODHash] lod=1 tiles=448 density=0x64bb55bd41e9fd42 mesh=0x17e89b7087bfe711 payload=0x2389c109eb780db6 topology=0x7eccd4cf560d0630
+[PipelineLODHash] lod=2 tiles=320 density=0x1edcfc338a395eaf mesh=0xc647d1e056e370cd payload=0xf81bba773df803ee topology=0xac68f4c0b6647735
+[PipelineLODHash] lod=3 tiles=208 density=0x580ede5c492925c7 mesh=0x30aeb3422a9382ef payload=0xb09b16ae1d40ac0d topology=0xd85e165b364261b5
+[PipelineLODHash] lod=4 tiles=240 density=0xfb11591772a3d18e mesh=0xebf2baee8764591b payload=0xe491d7ac9c0061ad topology=0xd618ac33b95ce494
+[PipelineLODHash] lod=5 tiles=144 density=0x2f8b7b7fb1e67258 mesh=0x4cd508cbe97344fd payload=0x2b6e96a6050458c9 topology=0x4ff6d0eda8988573
+[PipelineLODHash] lod=6 tiles=96 density=0x0114a34c8b8d6113 mesh=0xb1fec4d01ae1fa44 payload=0x3e50cfd429b8e950 topology=0x08090c96d15c1618
+[PipelineLODHash] lod=7 tiles=96 density=0x3836ed8cfce73418 mesh=0x40bc6589c5fc1aac payload=0x677349bcae16790f topology=0x36e3aa53192e6a6b
+[PipelineLODHash] lod=8 tiles=306 density=0x144f3c1fd722708b mesh=0xef77b28bf7fd9453 payload=0xe3f47b37fcd61489 topology=0x5a3c73e295494e04
+[PipelineExactQueryHash] probes=9 density=0x7b7c50ac24ccadcc unclamped=0x7b7c50ac24ccadcc detail=0xefcba20c0c70c415 collision=0xe604823a249029bf path=direct-Core-queries

Standalone/Tools/verify/verify.py

@@ -125,10 +125,11 @@ def owner_hash_baseline(recipe: str, style: int) -> tuple[Path, str]:
         return (BASELINES / "owner-hash/canonical/owner-hash-surface-world-style1-v212.baseline",
                 "L67-v212")
     if recipe == "floating-islands" and style == 2:
-        # L74 disables a legacy sub-tile shortcut after its falsifier found false solids.
-        # Keep the old fixture intact and pin the restored full-grid density signature.
-        return (BASELINES / "owner-hash/canonical/owner-hash-floating-islands-style2-l74-fullgrid.baseline",
-                "L74-full-grid")
+        # L75 explicitly materializes every reference density sample. The older L74
+        # signature omitted samples skipped inside native uniform blocks; retain that
+        # fixture and pin the current full-grid signature separately.
+        return (BASELINES / "owner-hash/canonical/owner-hash-floating-islands-style2-l75-fullgrid.baseline",
+                "L75-full-grid")
     raise VerificationFailure(f"no pinned owner hash baseline for {recipe} style {style}")