# Linux48 report

## Whole-surface audit

`AuditWholeSurfaceL48.py` scans every LOD0 triangle in the route corridor plus 3 m and the chamber box plus 3 m. It welds shared edges, compares geometric face normals, and scores area-weighted normal variation, high-angle edge density, maximum jumps and sliver area in 1 m cells. Connected hot cells become located clusters. A separate floor pass bins the full floor patch at 0.25 m along the route and 0.5 m across it, removes a local moving-mean trend, and checks ripple and adjacent steps. Thresholds use ground-facing native patches from the same export. JSON results and red-triangle XY maps are emitted.

The detector has no general quadric residual or periodic-spectrum metric yet; terraces outside its floor patch rely on the normal-cluster measures. The control results are:

| Mesh | Result | Evidence |
|---|---|---|
| L45 ramp | Expected fail | One normal cluster, 0.669 m² |
| L46 entrance | Expected fail | 84.3 mm floor ripple; 159.1 mm largest step |
| L47 wall-foot | Expected fail | One 5-cell cluster, 5.243 m², 42 severe edges; floor profile 34.5/57.6 mm ripple/step |
| Plain native | Pass | No clusters; floor profile not present |
| L47 smooth floor | Pass | 0.59 mm ripple; 1.15 mm largest step |
| L48 candidate | **Fail** | Two clusters, 7.095 m² total, 65.5 severe edges, 303 flagged triangles; floor profile 34.5/57.6 mm |

The L47 cluster is at approximately `x=[-5,0], y=[22,25], z=[-505,-504] m`. At 0.188 m above the floor its wall-band p95 dihedral is 54.6° with a 160.4° maximum; the selected floor rails did not reach this band. The complete control output is in `Saved/Linux/l48/whole-surface-audit.json`.

## Teeth measurement and attempted fix

The L47 measurements localize the teeth to the floor-cap/bore-wall junction. The post-stamp cap has a hard radial cutoff there, and the floor-adjacent re-carve also uses a non-SDF weighted blend. A re-carve fade alone left the teeth in the capture. The final trial replaced both cavern cap gates with a rounded max of the sloped-floor distance and radial bore distance, restoring the L47 re-carve weight. This reduced the apparent tooth height in the capture but did not clear the whole-surface gate; the final mesh has more flagged area and a second cluster. The hard cap edge is implicated, but the cause is not proven and this is not a validated fix.

## Hashes and cost

Clang and GCC builds used source stamp `05ea28750b2ee89aa61655c386c6d74a6841c4d071374cda03c73a89b5efb578`.

Demo-off whole-view hashes match L47 exactly at W1 and W12:

- floating-islands: density `598e9daaa1744ccb`, mesh `3114e0f4f6dbf734`, payload `c49c4e48bff74089`, topology `cadd4edd10d4d8ef`.
- surface-world: density `7dc75e2c09302258`, mesh `0cb34c40ceec4ce3`, payload `9d23e8c46b515cf1`, topology `2962c9464991eedd`.

Fast took 202.7 s. Medium took 637.6 s; the whole-surface stage took 161.8 s and failed on L48. Full and its five-pair cost comparison were not run because medium did not pass. All build and verification processes used `TMPDIR=Saved/Linux/l48/tmp`; no command wrote to `/tmp`.

## Tiers and captures

| Tier | Result |
|---|---|
| Fast | Pass, 202.7 s |
| Medium | Fail, 637.6 s: L48 whole-surface gate |
| Full | Not run: medium prerequisite failed |

The five captures are `ground-entrance.jpg`, `entrance-looking-in.jpg`, `overview-entrance-and-chamber.jpg`, `inside-to-dais.jpg`, and `entrance-floor-low.jpg` in `captures/`. Flag maps: `flagged-regions-L47-wall-foot-control.svg` and `flagged-regions-L48-final.svg` (red flagged triangles, gray ROI, blue route).

## Failed runs

- The first fast invocation had no built binary; after the Clang/GCC builds, fast passed.
- Bypassing the post-stamp floor cap failed entrance rails. Broad SmoothMin/cap-mask trials either closed the mouth or failed the built-shape check; one planar mouth patch measured 5.575 m².
- Radial re-carve fades at 0.5 m and 1 m preserved the rails but left visible teeth and failed the whole-surface audit. Changing the support inset had no mesh effect.
- The final rounded-cap trial passed the legacy rails and shape checks, but failed medium with the clusters above. The 15-trial budget is exhausted. No full tier, commit, push or stash was performed.

## Orchestrator review (Claude)

Split. **The whole-surface audit is the result of this round,** and it's committed here as a tool, not yet wired into
the tiers. All three historical defects fail it (L45 ramp, L46 entrance, L47 wall foot) and plain native terrain
passes. It also shows that L47's floor near the walls carries 34.5 mm ripple and a 57.6 mm step, which the three
rails never sampled. **The Core change (rounded cap) did not pass** and is parked with the tier wiring on
`wip/l48-surface-audit`. Wiring the gate now would turn medium red on HEAD, because the flagged demo still has the
teeth. `assembler/world` stays on L47 Core. L49 builds the floor and bore as one SDF, with a filleted floor/wall
corner, before stamps, instead of patching with a post-pass cap.