feat(core): profiled heightfields, slice 1: periodicHills, mirroredRelief, flatField (L53); research R22

WorldAssemblySurfaceProfileV1 on the native SurfaceWorld recipe and plan; version 0 'natural' is omitted
from serialized identity, so the owner world is unchanged. periodicHills (seeded cosine hills, plan-time
grade <= 15 deg), mirroredRelief (cap mirrors the floor by lambda, clearance checked) and flatField share
one profile function for points, lattice classification and exact cosine-extrema intervals (0 interval
misses in brute-force audits). Style-override fixtures with planned passages. Cold whole view about 1.33 s
for each profile vs 1.74 s natural SW (Clang). Owner hashes identical to L52; fast/medium/full PASS.
Research R22: SurfaceWorld critical path to about 1 s.

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

Standalone/Research/WorldAssemblerM3/Linux53/REPORT.md

@@ -0,0 +1,53 @@
+# Linux 53 — profiled heightfields, slice 1
+
+## Profile API
+
+`WorldAssemblySurfaceProfileV1` is attached to the native SurfaceWorld recipe and stratum plan. Version 0 is the all-zero `natural` profile; it is omitted from serialized identity, preserving the existing owner world. Non-default profiles use version 1, serialize into recipe and plan JSON, and contribute to canonical hashes. Dimensions use fixed metre-derived subvoxels, and periodic phases are derived deterministically from the recipe seed and axis.
+
+## Profiles and bounds
+
+- **natural** retains today's noise heightfield.
+- **periodicHills** uses `h = h0 + Ax cos(2πx/Lx + φx) + Ay cos(2πy/Ly + φy)`. The fixture uses `Ax=Ay=1.5 m`, `Lx=Ly=96 m`; seeded phases are Q0.32 turns `1258571205` and `82173144`. Its maximum analytic grade is 7.90° (the plan-time limit is 15°). Supported ranges follow R20: amplitudes 0.5–3 m and wavelengths 80–160 m.
+- **mirroredRelief** uses `g = Ax cos(...) + Ay cos(...)`, floor `h0+g`, and ceiling `c0−λg`. The fixture uses 1.5 m amplitudes, 128 m wavelengths, and `λ=0.875`. R20 ranges are 0.5–2 m, 80–160 m, and `λ=0.75–1`. The plan checks `c0−h0−(1+λ)(Ax+Ay)` against the required clearance; the fixture requests 8 m. Its maximum grade is 5.94°.
+- **flatField** sets the floor to `h0` and retains the plan's flat cap.
+
+For each horizontal box, the cosine range checks its endpoints and all included stationary points; spans of a full period use `[-1,1]`. The two axis ranges are combined for floor and mirrored-cap bounds. Fixed-point rounding is padded outward by two subvoxels; flat-field bounds are constant. The same profile function feeds point evaluation, lattice classification, and intervals. Each profile audit checked 96 boxes against 23,328 brute-force density samples: zero interval misses and zero classifier mismatches. Each also certified 24 air and 24 solid boxes; the separate bound audit checked 265 boxes and 7,155 samples. The density sign remains negative for solid and nonnegative for air.
+
+## Fixtures, routes, and captures
+
+The fixtures are named `style-override-profile-periodicHills.json`, `style-override-profile-mirroredRelief.json`, and `style-override-profile-flatField.json` under `Saved/Linux/l53/fixtures/`. Each plans an inter-stratum arrival/departure passage and a 32-segment supported route. Profile proofs and passage audits pass, including interface-band and negative-thickness controls. Measured route grades are 7.904°, 5.945°, and 0° respectively; mirrored clearance is at least the requested 8 m.
+
+Eye-height and overview captures all pass quality gates (6/6):
+
+- Periodic hills: [eye](captures/periodicHills-eye.jpg), [overview](captures/periodicHills-overview.jpg)
+- Mirrored relief: [eye](captures/mirroredRelief-eye.jpg), [overview](captures/mirroredRelief-overview.jpg)
+- Flat field: [eye](captures/flatField-eye.jpg), [overview](captures/flatField-overview.jpg)
+
+## Timings and hashes
+
+Cold whole-view readiness, seconds:
+
+| Compiler | Natural SurfaceWorld | periodicHills | mirroredRelief | flatField |
+|---|---:|---:|---:|---:|
+| Clang 19 | 1.742 | 1.336 | 1.323 | 1.330 |
+| GCC | 1.911 | 1.436 | 1.409 | 1.382 |
+
+Both compilers were freshly rebuilt from this source stamp with FP contraction off and 12 jobs. Every profile is under the 1.75 s budget; periodic hills and flat field are faster than their natural SurfaceWorld reference. Profile layout IDs are `bf3b90bc4678497e` (periodic), `bd45e0817b6338fa` (mirrored), and `dea9d3b61447f9b1` (flat).
+
+Floating Islands and natural SurfaceWorld owner hashes each match L52 exactly: 12/12 canonical rows on Clang and GCC at W12. Profile worker hashes match at W1/W8/W12, and seeded random-camera geometry/material hashes match across Clang and GCC. Source stamp: `99389e29037f59841b46b31f16899355b718ba8def14ff73c43f8900dbb75c0b`.
+
+## Verification and failed runs
+
+Fast passed in 149.6 s; medium passed in 606.2 s; full passed once in 1,088.3 s. Full included 30-cell determinism and five paired baseline cost measurements. The median candidate changes were +0.87% for SurfaceWorld and +0.84% for Floating Islands.
+
+Earlier trials exposed a lower-landing capsule-support failure and a transition-audit harness short-circuit; route radius conversion was corrected and transition checks were split. One medium attempt then failed its speed gate because passage audits contaminated `whole_view_ready` (21.666 s). The final tier measures cold views separately without audit flags and passes at the times above. No final tier gates failed.
+
+## Orchestrator review (Claude)
+
+Accepted as code. The stamp matches the final Clang and GCC builds (`99389e29…`); the owner hashes are identical to
+L52; profile proofs show 0 misses. **All three profiles run faster than natural SW** (about 1.33 s vs 1.74 s on Clang).
+**The captures don't show the profiles.** The eye views are a single soft horizon against black: the cap is never
+visible, so mirrored relief can't be judged. The "periodicHills overview" frames the FI anchor spiral column from the
+upper strate, which still shows its old shard and terrace artifacts, instead of the hills. The next profile round
+must frame the hill field and the mirrored ceiling, for example a wide eye-level view with the cap in frame and a
+high oblique overview over several periods.