Route planning for an upper SurfaceWorld failed on long candidate chords over steep relief; chords
are now capped to the arrival/departure radii on an 8 m centre grid with an origin-proximity cost
(21.5 m walk, about 4 deg). The departure passage starts at the SW ground and tunnels down through rock.
FI -> SW -> TN fixture: all 4 styles pass every passage audit on both compilers. FloorProfileBlend
now checks endpoint height/tangent seams (step and tangent-step negative controls detected). Owner
world hashes unchanged; 30/30 determinism; cost within noise.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CSFYgsdW8ejZSyiMf4qRSX
