research: passage exclusion envelope at plan time (L148, 7/16; kept as patch)

Seed-2 shell carver measured: vertical-shafts route-edge-0, the layer's own connection edge from the 2-3 lower
mouth. Connection edges legitimately run beside the passage 12-20 m from the mouth, so an 8 m mouth-sphere exclusion
rejects 9/16 otherwise valid plans. Points to one continuous tube across the mouth instead of two overlapping ones.

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

Standalone/Research/WorldAssemblerM3/Linux148/REPORT.md

@@ -0,0 +1,29 @@
+# Linux148 — passage exclusion envelope
+
+**Result:** The shared plan-time bounds audit and its negative control work, and the L147 seed-2 carver is identified. The 8 m mouth joint is too small for the existing route candidates: both composed matrices pass only **7/16** seeds. Per the three-failure stop rule, this round stops without another planner adjustment and is not ready to promote.
+
+## Root cause and rule
+
+The L147 Vertical Shafts seed-2 wall sample at `(-21.678, -1.714, -888.614) m` is carved by `vertical-shafts/strate-3/route-edge-0`. At that point its native tube/floor SDF combines to about `-0.553 m`, predicting `+2.21` Core voxels of air; the observed native density is `+2.341949`. No other cave primitive has a negative native SDF there. The edge's start anchor is `passage/2-3/0/lower-mouth`, confirming this sample lies in its passage connection.
+
+The shared gate samples the resolved passage spline, expands it by the 1.053 m shell/influence reach, and checks each layer primitive's conservative AABB against that envelope. It permits overlap only for a named passage mouth, within an 8 m sphere (the planner's 2 m overlap plus 6 m lead). Other overlap rejects the graph before it is written into the layout. A forced AABB at a passage centerline is rejected as the negative control.
+
+The shared Core API is generic; this round wires it through `PlanResolvedCavernNetworkV1`, used by Tunnel Network and Vertical Shafts. Other layer planners must call it when they resolve their primitive bounds.
+
+The mouth radius is the limiting assumption. Existing route-edge bounds in Tunnel Network seeds 0, 1, 4, and 7 meet passage `1-2` at 12.5–19.6 m from the mouth; seed 8 also has room bounds at 17.5–20.5 m. These are connected route candidates, but they fall outside the 8 m sphere. In seed 10, `vertical-shafts/strate-3/shaft-1/primitive-0` also overlaps passage `2-3`; it has no mouth association and remains a separate candidate to resolve.
+
+## Measurements and checks
+
+- Clang 19 and GCC builds passed with source stamp `593551a985ec0d1acc271260e4c8f15a5261c90edb60e33a56ed6df27e269ffb`.
+- Tunnel Network: **7/16**; full runs were seeds 2, 3, 5, 6, 9, 11, and 12. Vertical Shafts: **7/16**, the same seeds. The other nine seeds in each matrix were rejected by the plan-time exclusion audit. The run logs and per-seed layouts are under `Saved/Linux/l148/seeds/`.
+- Across the seven full runs in each matrix: 2,186,289 passage-interior capsule samples, zero solid; 53,262 shell wall samples, zero violations. Passage, ripple, and negative-control gates passed on those runs. Seed 2's passage `2-3` had zero wall samples outside the mouth joint, so its shell result has no wall coverage beyond that joint.
+- The passing layouts match their L147 stable identities. Seed 2 is `resolved-layout-v3-fnv64:64988eac83c0220c`.
+- Fast tier passed in 362.6 s: `Saved/Linux/l148/fast/fast-summary.json`.
+- Clang/GCC W1/W8/W12 passed on seed 2: 13 pipeline hash lines and the resolved-layout identity matched across all six runs. Summary: `Saved/Linux/l148/determinism/summary.json`.
+- `git diff --check` and Python syntax checks passed. No Unreal build was run.
+
+The successful outputs remain evaluator v237 and layout-identical to L147. No baselines or captures were added. The nine rejected seeds produced no resolved layout, so there is no accepted before/after scene to capture. This is an incomplete, unpromoted planner change.
+
+## Remaining risk
+
+The audit catches conservative-bounds conflicts, but the current mouth sphere does not cover the existing connected-route bounds, and the optional shaft collision needs a deterministic candidate decision. The 16/16 requirement is unmet. No Unreal `Source/` files changed.