diff --git a/.github/workflows/pack-checks.yml b/.github/workflows/pack-checks.yml
new file mode 100644
index 0000000..4076a72
--- /dev/null
+++ b/.github/workflows/pack-checks.yml
@@ -0,0 +1,61 @@
+# The pack CI (roadmap 34 E2): every PR to main runs the pack tools' unit tests and
+# `kit-build check` over EVERY pack — manifest schema (incl. lods / behavior), GLB size, triangle
+# budgets, texture caps, emissive policy, scale, pivot, LOD files, the static z-fight probe and
+# thumbnails. Failures that are known and accepted live in tools/kit-build/allow.json with a reason.
+# Make the "pack-checks" job a REQUIRED status check on main (Settings → Branches / Rulesets).
+name: pack checks
+
+on:
+  pull_request:
+    branches: [main]
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: pack-checks-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  pack-checks:
+    name: pack-checks
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    steps:
+      - uses: actions/checkout@v7
+
+      - uses: actions/setup-node@v7
+        with:
+          node-version: 24
+          cache: npm
+          cache-dependency-path: tools/meshy/package-lock.json
+
+      - name: install the pack tools (tools/meshy — no browser, no Meshy key)
+        working-directory: tools/meshy
+        run: npm ci --no-audit --no-fund
+
+      - name: unit tests (kit-build, lod, the kit builds, meshy)
+        run: |
+          node --test tools/kit-build/test/*.test.mjs tools/lod/test/*.test.mjs \
+            tools/architecture-kit/test/*.test.mjs tools/scifi-kit/test/*.test.mjs \
+            tools/town-kit/test/*.test.mjs tools/anim/test/*.test.mjs interior-kit/_src/test/*.test.mjs
+          (cd tools/meshy && npm test)
+
+      - name: kit-build check (every pack)
+        run: node tools/kit-build/kit-build.mjs check --summary "$GITHUB_STEP_SUMMARY" --json pack-check.json
+
+      - name: budget report
+        if: always()
+        run: node tools/kit-build/kit-build.mjs report --md pack-budget.md
+
+      - uses: actions/upload-artifact@v7
+        if: always()
+        with:
+          name: pack-check
+          path: |
+            pack-check.json
+            pack-budget.md
+          if-no-files-found: ignore
diff --git a/README.md b/README.md
index e73e0f5..90fcc51 100644
--- a/README.md
+++ b/README.md
@@ -21,6 +21,9 @@ props-kit/                       Props & Interiors: 33 furnishing / dressing / g
 scifi-kit/                       Sci-fi & Modern Kit: 28 snap-together station pieces + dressing
                                  on the 1 m grid (CC0, made with Meshy.ai; kit.md = how to build)
 tools/scifi-kit/                 its reproducible build (Meshy jobs, post-processing, procedural pieces)
+tools/kit-build/                 THE pack build tool (post step, texture cap, emissive policy, decimate
+                                 to budget, LODs, thumbnails, budget report) and the pack CI checks —
+                                 see tools/kit-build/README.md
 tools/lod/                       no z-fighting (defight) + offline LODs: <name>.lod1/.lod2.glb and
                                  each row's "lods" field — see tools/lod/README.md
 interactive-kit/                 Interactive Kit: 19 animated, functional pieces — doors WITH frames,
@@ -45,6 +48,14 @@ Each `index.json` row: `{name, title, value | zip, attribution, copyright, licen
 installable pack. The formats are documented in the app repo's
 [PACKS.md](https://github.com/theprototype-app/core/blob/main/PACKS.md).
 
+## Checks
+
+Every PR to `main` runs `.github/workflows/pack-checks.yml`: the pack tools' unit tests and
+`node tools/kit-build/kit-build.mjs check` over every pack (manifest schema incl. `lods` /
+`behavior`, GLB ≤ 5 MiB, triangle budgets, texture caps, emissive policy, scale, pivot, LOD
+files, the static z-fight probe, thumbnails). Run it locally before pushing
+(`cd tools/meshy && npm ci` once). A new pack needs its policy row in `tools/kit-build/packs.json`.
+
 ## Versioning
 
 The app pins a ref (`@format-1`, `PACKS_BASE` in core's `src/lib/packs.js`) so pack
diff --git a/architecture-kit/Block/screenshot/screenshot.webp b/architecture-kit/Block/screenshot/screenshot.webp
deleted file mode 100644
index e886f68..0000000
Binary files a/architecture-kit/Block/screenshot/screenshot.webp and /dev/null differ
diff --git a/default/SvelteRune/glTF-Binary/SvelteRune.glb b/default/SvelteRune/glTF-Binary/SvelteRune.glb
index f6a04b8..d624c7e 100644
Binary files a/default/SvelteRune/glTF-Binary/SvelteRune.glb and b/default/SvelteRune/glTF-Binary/SvelteRune.glb differ
diff --git a/interactive-kit/default.json b/interactive-kit/default.json
index f6ca80d..0c92267 100644
--- a/interactive-kit/default.json
+++ b/interactive-kit/default.json
@@ -10,7 +10,7 @@
       "type": "door",
       "clip": "open",
       "closeClip": "close",
-      "trigger": "click",
+      "trigger": "clik",
       "autoplay": false,
       "sound": "door",
       "collider": "follow"
@@ -51,7 +51,7 @@
   },
   {
     "name": "DoorDouble",
-    "label": "Double door in a sandstone wall (2 × 3 m)",
+    "label": "Double door in a sandstone wall (2 \u00d7 3 m)",
     "screenshot": "screenshot/screenshot.webp",
     "variants": {
       "glTF-Binary": "door-double.glb"
@@ -105,7 +105,7 @@
   },
   {
     "name": "Portcullis",
-    "label": "Portcullis in a gate wall (2 × 4.5 m)",
+    "label": "Portcullis in a gate wall (2 \u00d7 4.5 m)",
     "screenshot": "screenshot/screenshot.webp",
     "variants": {
       "glTF-Binary": "portcullis.glb"
@@ -351,7 +351,7 @@
   },
   {
     "name": "PressurePlate",
-    "label": "Pressure plate 1 × 1 m (steps sink it)",
+    "label": "Pressure plate 1 \u00d7 1 m (steps sink it)",
     "screenshot": "screenshot/screenshot.webp",
     "variants": {
       "glTF-Binary": "pressure-plate.glb"
diff --git a/interior-kit/_src/build.mjs b/interior-kit/_src/build.mjs
index 8ee86d0..7c2591c 100644
--- a/interior-kit/_src/build.mjs
+++ b/interior-kit/_src/build.mjs
@@ -15,27 +15,25 @@ import fs from 'node:fs';
 import os from 'node:os';
 import path from 'node:path';
 import { fileURLToPath } from 'node:url';
-import { createRequire } from 'node:module';
 import { ITEMS, pivotOf } from './items.mjs';
 import { PIECES, WALL_FACE } from './procedural.mjs';
 
-const TOOLS = process.env.MESHY_TOOLS ?? new URL('../../tools/meshy', import.meta.url).pathname;
+// the shared pack tooling (roadmap 34 E2: tools/kit-build instead of a fork per kit) — gltf-transform
+// comes through its loader, so the Documents here and its helpers are ONE module instance
+const { TOOLS, load, tool } = await import('../../tools/kit-build/lib/deps.mjs');
+const { gradeLinear: grade, inpaintBlack, repairNormals, flatForSync } = await import('../../tools/kit-build/lib/post.mjs');
 const STAGING = process.env.MESHY_STAGING ?? path.join(os.homedir(), '.code/lanes-30/meshy/staging');
 const REQUESTER = '33-pack-interior';
-const { postProcess } = await import(`${TOOLS}/lib/post.js`);
-const sharp = createRequire(`${TOOLS}/package.json`)('sharp');
-const { renderThumbs } = await import(`${TOOLS}/lib/thumb.js`);
-const { NodeIO } = await import(`${TOOLS}/node_modules/@gltf-transform/core/dist/index.js`);
-const { ALL_EXTENSIONS } = await import(`${TOOLS}/node_modules/@gltf-transform/extensions/dist/index.js`);
-const { mergeDocuments, dedup, prune, getBounds, unpartition, flatten, transformMesh, join, simplify, weld } = await import(`${TOOLS}/node_modules/@gltf-transform/functions/dist/index.js`);
-const { MeshoptSimplifier } = await import(`${TOOLS}/node_modules/meshoptimizer/index.js`);
+const { postProcess } = await tool('lib/post.js');
+const { renderThumbs } = await tool('lib/thumb.js');
+const { NodeIO } = await load('@gltf-transform/core');
+const { ALL_EXTENSIONS } = await load('@gltf-transform/extensions');
+const { mergeDocuments, dedup, prune, getBounds, unpartition, flatten, transformMesh, join, simplify, weld } = await load('@gltf-transform/functions');
+const { MeshoptSimplifier } = await load('meshoptimizer');
 
-// 33-pack-fix-lod's defight (tools/lod, its own PR): settles coplanar layers in Meshy meshes —
-// their materials are double-sided, so even OPPOSITE-facing coplanar layers flicker. Optional
-// until that PR is on main: without it the build warns and ships the meshes unsettled.
-const DEFIGHT = new URL('../../tools/lod/defight.mjs', import.meta.url).pathname;
-const { defightFile } = fs.existsSync(DEFIGHT) ? await import(DEFIGHT) : { defightFile: null };
-if (!defightFile) console.warn('WARNING: tools/lod/defight.mjs missing (33-pack-fix-lod) — Meshy meshes are NOT defighted');
+// 33-pack-fix-lod's defight (tools/lod): settles coplanar layers in Meshy meshes — their materials
+// are double-sided, so even OPPOSITE-facing coplanar layers flicker.
+const { defightFile } = await import('../../tools/lod/defight.mjs');
 
 const HERE = path.dirname(fileURLToPath(import.meta.url));
 const PACK = path.resolve(HERE, '..');
@@ -62,144 +60,6 @@ function sizeOf(doc) {
 	return { min: b.min, max: b.max, size: [0, 1, 2].map((i) => b.max[i] - b.min[i]) };
 }
 
-/** Colour-grade every base-colour texture: per-channel multiply (+ offset) */
-async function grade(doc, { mul, add = [0, 0, 0], only }) {
-	for (const mat of doc.getRoot().listMaterials()) {
-		const tex = mat.getBaseColorTexture();
-		const img = tex?.getImage();
-		if (!img) continue;
-		if (only === 'teal') {
-			// SELECTIVE: only teal-ish texels (green and blue well above red) — a painted cupboard
-			// darkens to the pack's deep teal while its marble top and brass stay as they are
-			const { data, info } = await sharp(Buffer.from(img)).removeAlpha().raw().toBuffer({ resolveWithObject: true });
-			for (let i = 0; i < data.length; i += 3) {
-				const [r, g, b] = [data[i], data[i + 1], data[i + 2]];
-				const k = Math.min(1, Math.max(0, (Math.min(g, b) - r - 12) / 30)); // soft mask
-				if (k <= 0) continue;
-				for (let c = 0; c < 3; c++) data[i + c] = Math.round(data[i + c] * (1 - k + k * mul[c]));
-			}
-			tex.setImage(await sharp(data, { raw: info }).jpeg({ quality: 86 }).toBuffer()).setMimeType('image/jpeg');
-			continue;
-		}
-		tex.setImage(await sharp(Buffer.from(img)).linear(mul, add).jpeg({ quality: 86 }).toBuffer()).setMimeType('image/jpeg');
-	}
-}
-
-/** Repair texels Meshy left unpainted (pure black holes in the atlas — the bed's headboard
- * showed one): diffuse the surrounding colour into every near-black texel. 0 credits. */
-async function inpaintBlack(doc, { max = 30 } = {}) {
-	let fixed = 0;
-	for (const mat of doc.getRoot().listMaterials()) {
-		const tex = mat.getBaseColorTexture();
-		const img = tex?.getImage();
-		if (!img) continue;
-		const { data, info } = await sharp(Buffer.from(img)).removeAlpha().raw().toBuffer({ resolveWithObject: true });
-		const { width: w, height: h } = info;
-		const hole = new Uint8Array(w * h);
-		let n = 0;
-		for (let i = 0; i < w * h; i++) if (Math.max(data[i * 3], data[i * 3 + 1], data[i * 3 + 2]) < max) (hole[i] = 1), n++;
-		if (!n) continue;
-		// onion-peel: fill hole texels that touch known texels with their neighbours' mean, repeat
-		for (let pass = 0; pass < 2048 && n; pass++) {
-			const next = [];
-			for (let y = 0; y < h; y++)
-				for (let x = 0; x < w; x++) {
-					const i = y * w + x;
-					if (!hole[i]) continue;
-					const acc = [0, 0, 0];
-					let k = 0;
-					for (const [dx, dy] of [[1, 0], [-1, 0], [0, 1], [0, -1], [1, 1], [-1, -1], [1, -1], [-1, 1]]) {
-						const xx = x + dx;
-						const yy = y + dy;
-						if (xx < 0 || yy < 0 || xx >= w || yy >= h) continue;
-						const j = yy * w + xx;
-						if (hole[j]) continue;
-						for (let c = 0; c < 3; c++) acc[c] += data[j * 3 + c];
-						k++;
-					}
-					if (k >= 2) next.push([i, acc.map((v) => Math.round(v / k))]);
-				}
-			if (!next.length) break;
-			for (const [i, col] of next) {
-				for (let c = 0; c < 3; c++) data[i * 3 + c] = col[c];
-				hole[i] = 0;
-				n--;
-				fixed++;
-			}
-		}
-		tex.setImage(await sharp(data, { raw: { width: w, height: h, channels: 3 } }).jpeg({ quality: 86 }).toBuffer()).setMimeType('image/jpeg');
-	}
-	return fixed;
-}
-
-/** Repair Meshy's broken vertex normals (every Meshy piece; the bed's headboard rendered a
- * black triangle): (1) a ZERO / NaN normal (Meshy ships a few) shades black — it takes the
- * area-weighted mean of its triangles' face normals; (2) a triangle whose vertex normals
- * point AGAINST its winding renders dark under the double-sided material — it gets its own
- * vertices carrying its face normal. Returns { zero, flipped }. */
-function repairNormals(doc) {
-	let fixed = 0;
-	let zero = 0;
-	for (const mesh of doc.getRoot().listMeshes())
-		for (const prim of mesh.listPrimitives()) {
-			const names = prim.listSemantics();
-			const attrs = names.map((s) => prim.getAttribute(s));
-			const P = prim.getAttribute('POSITION');
-			const N = prim.getAttribute('NORMAL');
-			const I = prim.getIndices();
-			if (!N || !I) continue;
-			{
-				const acc = new Float64Array(N.getCount() * 3);
-				const ix = I.getArray();
-				for (let t = 0; t < ix.length; t += 3) {
-					const [a, b, c] = [ix[t], ix[t + 1], ix[t + 2]].map((i) => P.getElement(i, []));
-					const u = [b[0] - a[0], b[1] - a[1], b[2] - a[2]];
-					const w = [c[0] - a[0], c[1] - a[1], c[2] - a[2]];
-					const n = [u[1] * w[2] - u[2] * w[1], u[2] * w[0] - u[0] * w[2], u[0] * w[1] - u[1] * w[0]];
-					for (let k = 0; k < 3; k++) for (let j = 0; j < 3; j++) acc[ix[t + k] * 3 + j] += n[j];
-				}
-				for (let i = 0; i < N.getCount(); i++) {
-					const n = N.getElement(i, []);
-					if (Math.hypot(...n) > 0.5) continue;
-					const m = [acc[i * 3], acc[i * 3 + 1], acc[i * 3 + 2]];
-					const l = Math.hypot(...m) || 1;
-					N.setElement(i, l > 1e-12 ? m.map((x) => x / l) : [0, 1, 0]);
-					zero++;
-				}
-			}
-			const arrays = attrs.map((a) => Array.from(a.getArray()));
-			const idx = Array.from(I.getArray());
-			for (let t = 0; t < idx.length; t += 3) {
-				const [a, b, c] = [idx[t], idx[t + 1], idx[t + 2]].map((i) => P.getElement(i, []));
-				const u = [b[0] - a[0], b[1] - a[1], b[2] - a[2]];
-				const w = [c[0] - a[0], c[1] - a[1], c[2] - a[2]];
-				const n = [u[1] * w[2] - u[2] * w[1], u[2] * w[0] - u[0] * w[2], u[0] * w[1] - u[1] * w[0]];
-				const len = Math.hypot(...n);
-				if (len < 1e-12) continue;
-				let neg = 0;
-				for (let k = 0; k < 3; k++) {
-					const vn = N.getElement(idx[t + k], []);
-					if (vn[0] * n[0] + vn[1] * n[1] + vn[2] * n[2] < 0) neg++;
-				}
-				if (neg < 2) continue;
-				for (let k = 0; k < 3; k++) {
-					const src = idx[t + k];
-					attrs.forEach((attr, j) => {
-						const size = attr.getElementSize();
-						const el = names[j] === 'NORMAL' ? n.map((x) => x / len) : attr.getElement(src, []);
-						arrays[j].push(...el.slice(0, size));
-					});
-					idx[t + k] = arrays[names.indexOf('POSITION')].length / 3 - 1;
-				}
-				fixed++;
-			}
-			if (!fixed) continue;
-			attrs.forEach((attr, j) => attr.setArray(new (attr.getArray().constructor)(arrays[j])));
-			I.setArray(new Uint32Array(idx));
-		}
-	return { zero, flipped: fixed };
-}
-
 async function buildMeshy(item, raw, out) {
 	const { wallLine, ...post } = item.post;
 	const report = await postProcess(raw, out, { ...post, pivot: post.pivot ?? 'bottom-center' });
@@ -214,7 +74,7 @@ async function buildMeshy(item, raw, out) {
 		if (wallLine) for (const mesh of doc.getRoot().listMeshes()) transformMesh(mesh, [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, WALL_FACE, 1]);
 		await io.write(out, doc);
 	}
-	const fight = defightFile ? await defightFile(out) : null;
+	const fight = await defightFile(out);
 	return { source: path.relative(STAGING, raw), trisIn: report.trisIn, ...(fight && fight.before ? { defight: { pairs: fight.before, dropped: fight.dropped, pushed: fight.pushed } } : {}), ...(item.grade ? { grade: item.grade.mul } : {}), ...(inpainted ? { inpainted } : {}), ...(normals.zero || normals.flipped ? { normalsRepaired: normals } : {}) };
 }
 
@@ -263,29 +123,6 @@ async function kitbash(list, out, maxTris = 7500) {
 	return { source: `kitbash: ${list.map((l) => l[0]).join(' + ')}`, trisIn: before };
 }
 
-/**
- * FLAT FOR SYNC (props-kit): every mesh node a direct child of the scene, one primitive per
- * mesh. Core's scene sync sends a nested Group with its WORLD pose and the receiver parents
- * it under the import root, so a nested import lands off by its own offset on peers.
- */
-async function flatForSync(doc) {
-	await doc.transform(flatten());
-	const scene = sceneOf(doc);
-	for (const node of [...scene.listChildren()]) {
-		const mesh = node.getMesh();
-		if (!mesh || mesh.listPrimitives().length < 2) continue;
-		mesh.listPrimitives().forEach((prim, i) => {
-			const name = `${node.getName()}_${prim.getMaterial()?.getName() || i}`;
-			const part = doc.createNode(name).setTranslation(node.getTranslation()).setRotation(node.getRotation()).setScale(node.getScale());
-			part.setMesh(doc.createMesh(name).addPrimitive(prim));
-			scene.addChild(part);
-		});
-		node.dispose();
-		mesh.dispose();
-	}
-	await doc.transform(prune());
-}
-
 const tag = (doc, item) => {
 	const scene = sceneOf(doc);
 	scene.setName(item.name);
diff --git a/nature-kit/build/finalize.mjs b/nature-kit/build/finalize.mjs
index ebe6f1e..60c6bdd 100644
--- a/nature-kit/build/finalize.mjs
+++ b/nature-kit/build/finalize.mjs
@@ -18,14 +18,15 @@ import { execFileSync } from 'node:child_process';
 import { createRequire } from 'node:module';
 import { pathToFileURL } from 'node:url';
 
-const TOOL = process.env.MESHY_TOOL || '/home/deck/.code/theprototype-app/packs-lane-30c-tools/tools/meshy';
+const TOOL = process.env.MESHY_TOOL || path.resolve(path.dirname(new URL(import.meta.url).pathname), '../../tools/meshy');
 const STAGING = process.env.MESHY_STAGING || path.join(os.homedir(), '.code/lanes-30/meshy/staging/30c-pack-nature');
 const require = createRequire(path.join(TOOL, 'package.json'));
-const sharp = require('sharp');
 const { NodeIO, Document } = require('@gltf-transform/core');
 const { ALL_EXTENSIONS } = require('@gltf-transform/extensions');
-const { flatten, clearNodeTransform, compactPrimitive, getBounds, mergeDocuments, unpartition, dedup, prune } = require('@gltf-transform/functions');
+const { getBounds, mergeDocuments, unpartition, dedup, prune } = require('@gltf-transform/functions');
 const { postProcess } = await import(pathToFileURL(path.join(TOOL, 'lib/post.js')).href);
+// the shared post steps (roadmap 34 E2: tools/kit-build instead of a fork per kit)
+const { cutBase, gradeHue: grade, dropEmissive } = await import('../../tools/kit-build/lib/post.mjs');
 
 const HERE = path.dirname(new URL(import.meta.url).pathname);
 const PACK = path.resolve(HERE, '..');
@@ -51,112 +52,6 @@ function stagingRaw(job, stage) {
 	return path.join(dir, `${stage}-${n}`, 'raw.glb');
 }
 
-/** Bake node transforms, then drop every triangle lying entirely below `frac` of the height
- * (Meshy likes to stand plants on a flat round "base" disc — on real terrain that reads as a
- * coaster). Returns the path of a cut copy. */
-async function cutBase(input, frac) {
-	const doc = await io.read(input);
-	await doc.transform(flatten());
-	for (const node of doc.getRoot().listNodes()) if (node.getMesh()) clearNodeTransform(node);
-	const scene = doc.getRoot().getDefaultScene() ?? doc.getRoot().listScenes()[0];
-	const b = getBounds(scene);
-	const cut = b.min[1] + frac * (b.max[1] - b.min[1]);
-	let dropped = 0;
-	for (const mesh of doc.getRoot().listMeshes()) {
-		for (const prim of mesh.listPrimitives()) {
-			const pos = prim.getAttribute('POSITION');
-			const idx = prim.getIndices();
-			const n = idx ? idx.getCount() : pos.getCount();
-			const get = (i) => (idx ? idx.getScalar(i) : i);
-			const keep = [];
-			for (let t = 0; t < n; t += 3) {
-				const a = get(t), c = get(t + 1), d = get(t + 2);
-				const ymax = Math.max(pos.getElement(a, [])[1], pos.getElement(c, [])[1], pos.getElement(d, [])[1]);
-				if (ymax < cut) dropped++;
-				else keep.push(a, c, d);
-			}
-			const arr = pos.getCount() > 65535 ? new Uint32Array(keep) : new Uint16Array(keep);
-			const acc = doc.createAccessor().setType('SCALAR').setArray(arr).setBuffer(pos.getBuffer());
-			prim.setIndices(acc);
-			compactPrimitive(prim);
-		}
-	}
-	await doc.transform(prune());
-	const out = path.join(TMP, `cut-${path.basename(path.dirname(path.dirname(input)))}-${Math.random().toString(36).slice(2, 7)}.glb`);
-	await io.write(out, doc);
-	return { out, dropped };
-}
-
-const rgb2hsv = (r, g, b) => {
-	const mx = Math.max(r, g, b), mn = Math.min(r, g, b), d = mx - mn;
-	let h = 0;
-	if (d) h = mx === r ? ((g - b) / d) % 6 : mx === g ? (b - r) / d + 2 : (r - g) / d + 4;
-	return [(h * 60 + 360) % 360, mx ? d / mx : 0, mx];
-};
-const hsv2rgb = (h, s, v) => {
-	const c = v * s, x = c * (1 - Math.abs(((h / 60) % 2) - 1)), m = v - c;
-	const [r, g, b] = h < 60 ? [c, x, 0] : h < 120 ? [x, c, 0] : h < 180 ? [0, c, x] : h < 240 ? [0, x, c] : h < 300 ? [x, 0, c] : [c, 0, x];
-	return [r + m, g + m, b + m];
-};
-const inRange = (h, [a, b]) => (a <= b ? h >= a && h <= b : h >= a || h <= b);
-
-/** Colour grade the base-colour textures: each rule moves pixels whose hue is in `hue`
- * (degrees, wraps) by `shift` degrees / scales saturation `sat` and value `val`, feathered
- * at the range edges so there is no hard seam. The 0-credit alternative to a retexture. */
-async function grade(file, rules) {
-	const doc = await io.read(file);
-	for (const mat of doc.getRoot().listMaterials()) {
-		const tex = mat.getBaseColorTexture();
-		if (!tex) continue;
-		const { data, info } = await sharp(Buffer.from(tex.getImage())).removeAlpha().raw().toBuffer({ resolveWithObject: true });
-		for (let i = 0; i < data.length; i += 3) {
-			let [h, s, v] = rgb2hsv(data[i] / 255, data[i + 1] / 255, data[i + 2] / 255);
-			let tint = null;
-			for (const r of rules) {
-				if (s < (r.minSat ?? 0.12) || !inRange(h, r.hue)) continue;
-				if (r.maxSat != null && s > r.maxSat) continue;
-				if ((r.minVal != null && v < r.minVal) || (r.maxVal != null && v > r.maxVal)) continue;
-				const [a, b] = r.hue;
-				const span = (b - a + 360) % 360 || 360;
-				const t = ((h - a + 360) % 360) / span; // 0..1 across the range
-				const w = r.feather === false ? 1 : Math.min(1, Math.min(t, 1 - t) / 0.15); // feather the outer 15%
-				h = (h + (r.shift ?? 0) * w + 360) % 360;
-				s = Math.min(1, s * (1 + ((r.sat ?? 1) - 1) * w));
-				v = Math.min(1, v * (1 + ((r.val ?? 1) - 1) * w));
-				if (r.tint) tint = [r.tint, (r.amount ?? 0.3) * w, v];
-				break;
-			}
-			let [R, G, B] = hsv2rgb(h, s, v);
-			if (tint) {
-				// multiply-style tint: keep the painted value, pull the colour toward the tint
-				const [hex, k, vv] = tint;
-				const c = [1, 3, 5].map((j) => parseInt(hex.slice(j, j + 2), 16) / 255);
-				const cmax = Math.max(...c);
-				[R, G, B] = [R, G, B].map((x, j) => x * (1 - k) + (c[j] / cmax) * vv * k);
-			}
-			data[i] = R * 255; data[i + 1] = G * 255; data[i + 2] = B * 255;
-		}
-		const jpg = await sharp(data, { raw: info }).jpeg({ quality: 86 }).toBuffer();
-		tex.setImage(new Uint8Array(jpg)).setMimeType('image/jpeg');
-	}
-	await io.write(file, doc);
-}
-
-/** Meshy-6 refines sometimes paint a NON-black emissive map (the oak's canopy: mean 33-47 of
- * 255), which makes foliage glow at night and wash out by day. Nothing in a nature kit emits
- * light, so the map and factor go (meshy-post only drops a fully black one). */
-async function dropEmissive(file) {
-	const doc = await io.read(file);
-	let n = 0;
-	for (const mat of doc.getRoot().listMaterials()) {
-		if (mat.getEmissiveTexture() || mat.getEmissiveFactor().some((v) => v > 0)) n++;
-		mat.setEmissiveTexture(null).setEmissiveFactor([0, 0, 0]);
-	}
-	await doc.transform(prune());
-	await io.write(file, doc);
-	return n;
-}
-
 /** merge built items into one GLB; parts: [{item, pos, rotY, scale}] */
 async function kitbash(parts, out, pivot = 'bottom-center') {
 	const doc = new Document();
@@ -211,7 +106,7 @@ for (const it of spec.items) {
 	if (it.kind === 'meshy') {
 		let src = stagingRaw(it.job, it.stage ?? 'refine');
 		let dropped = 0;
-		if (it.cutBase) ({ out: src, dropped } = await cutBase(src, it.cutBase));
+		if (it.cutBase) ({ out: src, dropped } = await cutBase(src, it.cutBase, TMP));
 		await postProcess(src, out, it.post ?? {});
 		if (!it.keepEmissive) await dropEmissive(out);
 		if (it.grade) await grade(out, it.grade);
diff --git a/nature-kit/build/grass.mjs b/nature-kit/build/grass.mjs
index a399043..ff98c52 100644
--- a/nature-kit/build/grass.mjs
+++ b/nature-kit/build/grass.mjs
@@ -9,7 +9,7 @@
 import path from 'node:path';
 import { createRequire } from 'node:module';
 
-const TOOL = process.env.MESHY_TOOL || '/home/deck/.code/theprototype-app/packs-lane-30c-tools/tools/meshy';
+const TOOL = process.env.MESHY_TOOL || path.resolve(path.dirname(new URL(import.meta.url).pathname), '../../tools/meshy');
 const require = createRequire(path.join(TOOL, 'package.json'));
 const sharp = require('sharp');
 const { Document, NodeIO } = require('@gltf-transform/core');
diff --git a/nature-kit/build/leaves.mjs b/nature-kit/build/leaves.mjs
index cd8df65..7e48a3f 100644
--- a/nature-kit/build/leaves.mjs
+++ b/nature-kit/build/leaves.mjs
@@ -8,7 +8,7 @@
 import path from 'node:path';
 import { createRequire } from 'node:module';
 
-const TOOL = process.env.MESHY_TOOL || '/home/deck/.code/theprototype-app/packs-lane-30c-tools/tools/meshy';
+const TOOL = process.env.MESHY_TOOL || path.resolve(path.dirname(new URL(import.meta.url).pathname), '../../tools/meshy');
 const require = createRequire(path.join(TOOL, 'package.json'));
 const sharp = require('sharp');
 const { Document, NodeIO } = require('@gltf-transform/core');
diff --git a/nature-kit/build/render.mjs b/nature-kit/build/render.mjs
index 9444226..4f1d54d 100644
--- a/nature-kit/build/render.mjs
+++ b/nature-kit/build/render.mjs
@@ -9,7 +9,7 @@ import fs from 'node:fs';
 import path from 'node:path';
 import { createRequire } from 'node:module';
 
-const TOOL = process.env.MESHY_TOOL || '/home/deck/.code/theprototype-app/packs-lane-30c-tools/tools/meshy';
+const TOOL = process.env.MESHY_TOOL || path.resolve(path.dirname(new URL(import.meta.url).pathname), '../../tools/meshy');
 const require = createRequire(path.join(TOOL, 'package.json'));
 const { chromium } = require('playwright-core');
 const sharp = require('sharp');
diff --git a/nature-kit/build/slope.mjs b/nature-kit/build/slope.mjs
index 9fa3ebd..de20370 100644
--- a/nature-kit/build/slope.mjs
+++ b/nature-kit/build/slope.mjs
@@ -3,7 +3,7 @@
 // of its upward-facing triangles (0° = flat). `node slope.mjs Hill/glTF-Binary/Hill.glb`
 import path from 'node:path';
 import { createRequire } from 'node:module';
-const TOOL = process.env.MESHY_TOOL || '/home/deck/.code/theprototype-app/packs-lane-30c-tools/tools/meshy';
+const TOOL = process.env.MESHY_TOOL || path.resolve(path.dirname(new URL(import.meta.url).pathname), '../../tools/meshy');
 const require = createRequire(path.join(TOOL, 'package.json'));
 const { NodeIO } = require('@gltf-transform/core');
 const doc = await new NodeIO().read(process.argv[2]);
diff --git a/nature-kit/build/water.mjs b/nature-kit/build/water.mjs
index d152cf5..4950d6b 100644
--- a/nature-kit/build/water.mjs
+++ b/nature-kit/build/water.mjs
@@ -8,7 +8,7 @@
 import path from 'node:path';
 import { createRequire } from 'node:module';
 
-const TOOL = process.env.MESHY_TOOL || '/home/deck/.code/theprototype-app/packs-lane-30c-tools/tools/meshy';
+const TOOL = process.env.MESHY_TOOL || path.resolve(path.dirname(new URL(import.meta.url).pathname), '../../tools/meshy');
 const require = createRequire(path.join(TOOL, 'package.json'));
 const sharp = require('sharp');
 const { Document, NodeIO } = require('@gltf-transform/core');
diff --git a/props-kit/_src/build.mjs b/props-kit/_src/build.mjs
index d351b3f..bec7dce 100644
--- a/props-kit/_src/build.mjs
+++ b/props-kit/_src/build.mjs
@@ -11,18 +11,19 @@ import os from 'node:os';
 import path from 'node:path';
 import { fileURLToPath } from 'node:url';
 import { ITEMS } from './items.mjs';
-import { createRequire } from 'node:module';
 import { PIECES, appendFlames } from './procedural.mjs';
 
-const TOOLS = process.env.MESHY_TOOLS ?? '/home/deck/.code/theprototype-app/packs-lane-30c-tools/tools/meshy';
+// the shared pack tooling (roadmap 34 E2: tools/kit-build instead of a fork per kit) — gltf-transform
+// comes through its loader, so the Documents here and its helpers are ONE module instance
+const { TOOLS, load, tool } = await import('../../tools/kit-build/lib/deps.mjs');
+const { gradeLinear: grade, albedoGlow, flatForSync } = await import('../../tools/kit-build/lib/post.mjs');
 const STAGING = process.env.MESHY_STAGING ?? path.join(os.homedir(), '.code/lanes-30/meshy/staging');
 const REQUESTER = '30c-pack-props';
-const { postProcess } = await import(`${TOOLS}/lib/post.js`);
-const sharp = createRequire(`${TOOLS}/package.json`)('sharp');
-const { renderThumbs } = await import(`${TOOLS}/lib/thumb.js`);
-const { NodeIO } = await import(`${TOOLS}/node_modules/@gltf-transform/core/dist/index.js`);
-const { ALL_EXTENSIONS } = await import(`${TOOLS}/node_modules/@gltf-transform/extensions/dist/index.js`);
-const { mergeDocuments, dedup, prune, getBounds, unpartition, flatten } = await import(`${TOOLS}/node_modules/@gltf-transform/functions/dist/index.js`);
+const { postProcess } = await tool('lib/post.js');
+const { renderThumbs } = await tool('lib/thumb.js');
+const { NodeIO } = await load('@gltf-transform/core');
+const { ALL_EXTENSIONS } = await load('@gltf-transform/extensions');
+const { mergeDocuments, dedup, prune, getBounds, unpartition } = await load('@gltf-transform/functions');
 
 const HERE = path.dirname(fileURLToPath(import.meta.url));
 const PACK = path.resolve(HERE, '..');
@@ -57,25 +58,13 @@ function autoFlames(kind, b) {
 	return [];
 }
 
-/** Colour-grade every base-colour texture: per-channel multiply (+ offset), so a piece
- * Meshy painted off-palette (a pale pine table) matches the kit's oak without a paid retexture. */
-async function grade(doc, { mul, add = [0, 0, 0] }) {
-	for (const mat of doc.getRoot().listMaterials()) {
-		const tex = mat.getBaseColorTexture();
-		const img = tex?.getImage();
-		if (!img) continue;
-		tex.setImage(await sharp(Buffer.from(img)).linear(mul, add).jpeg({ quality: 86 }).toBuffer()).setMimeType('image/jpeg');
-	}
-}
-
 async function buildMeshy(item, raw, out) {
 	const report = await postProcess(raw, out, { ...item.post, pivot: item.post.pivot ?? 'bottom-center' });
 	if (item.flames || item.grade || item.glow) {
 		const doc = await io.read(out);
 		if (item.grade) await grade(doc, item.grade);
-		// glow: the albedo doubles as the emissive map, so bright panes (a lantern's amber
-		// glass) light up while dark metal stays dark — a lit look with no extra texture
-		if (item.glow) for (const mat of doc.getRoot().listMaterials()) mat.setEmissiveTexture(mat.getBaseColorTexture()).setEmissiveFactor([item.glow, item.glow * 0.8, item.glow * 0.55]);
+		// glow: the albedo doubles as the emissive map (kit-build's albedoGlow)
+		if (item.glow) albedoGlow(doc, item.glow);
 		if (item.flames) appendFlames(doc, Array.isArray(item.flames) ? item.flames : autoFlames(item.flames, sizeOf(doc)));
 		await io.write(out, doc);
 	}
@@ -113,35 +102,6 @@ async function crateStack(out) {
 }
 const KITBASH = { crateStack };
 
-/**
- * FLAT FOR SYNC: every mesh node a direct child of the scene, one primitive per mesh.
- * Core's scene sync (commandsHandler sendObject) sends a leaf mesh with its LOCAL pose
- * but a nested Group / Object3D-with-children with its WORLD pose, which the receiver
- * then parents under the import root — so on a peer every nested level adds the
- * object's position again (measured: a placed Rug sat 2× its drop offset away on peer
- * B). GLTFLoader turns a multi-primitive mesh into a Group, so primitives are split to
- * one mesh each; flatten() lifts nested nodes to the scene with baked transforms.
- * @param {any} doc
- */
-async function flatForSync(doc) {
-	await doc.transform(flatten());
-	const root = doc.getRoot();
-	const scene = root.getDefaultScene() ?? root.listScenes()[0];
-	for (const node of [...scene.listChildren()]) {
-		const mesh = node.getMesh();
-		if (!mesh || mesh.listPrimitives().length < 2) continue;
-		mesh.listPrimitives().forEach((prim, i) => {
-			const name = `${node.getName()}_${prim.getMaterial()?.getName() || i}`;
-			const part = doc.createNode(name).setTranslation(node.getTranslation()).setRotation(node.getRotation()).setScale(node.getScale());
-			part.setMesh(doc.createMesh(name).addPrimitive(prim));
-			scene.addChild(part);
-		});
-		node.dispose();
-		mesh.dispose();
-	}
-	await doc.transform(prune());
-}
-
 const report = {};
 const reportFile = path.join(HERE, 'build-report.json');
 const prev = fs.existsSync(reportFile) ? JSON.parse(fs.readFileSync(reportFile, 'utf8')) : {};
diff --git a/props-kit/_src/cover.mjs b/props-kit/_src/cover.mjs
index 30d4c73..0ceca9a 100644
--- a/props-kit/_src/cover.mjs
+++ b/props-kit/_src/cover.mjs
@@ -9,7 +9,7 @@ import path from 'node:path';
 import { fileURLToPath } from 'node:url';
 import { createRequire } from 'node:module';
 
-const TOOLS = process.env.MESHY_TOOLS ?? '/home/deck/.code/theprototype-app/packs-lane-30c-tools/tools/meshy';
+const TOOLS = process.env.MESHY_TOOLS ?? new URL('../../tools/meshy', import.meta.url).pathname;
 const { NodeIO } = await import(`${TOOLS}/node_modules/@gltf-transform/core/dist/index.js`);
 const { ALL_EXTENSIONS } = await import(`${TOOLS}/node_modules/@gltf-transform/extensions/dist/index.js`);
 const { mergeDocuments, dedup, prune, unpartition } = await import(`${TOOLS}/node_modules/@gltf-transform/functions/dist/index.js`);
diff --git a/props-kit/_src/procedural.mjs b/props-kit/_src/procedural.mjs
index 9793edb..3ca580e 100644
--- a/props-kit/_src/procedural.mjs
+++ b/props-kit/_src/procedural.mjs
@@ -11,11 +11,13 @@ import fs from 'node:fs';
 import path from 'node:path';
 import { SWATCHES, rugSvg, tapestrySvg, jpeg } from './textures.mjs';
 
-const TOOLS = process.env.MESHY_TOOLS ?? '/home/deck/.code/theprototype-app/packs-lane-30c-tools/tools/meshy';
+// tools/meshy through the shared loader (roadmap 34 E2): the build hands its Documents to appendFlames,
+// so gltf-transform must be the same module instance as the build's
+const { TOOLS, load } = await import('../../tools/kit-build/lib/deps.mjs');
 const THREE = await import(`${TOOLS}/node_modules/three/build/three.module.js`);
 const { mergeGeometries } = await import(`${TOOLS}/node_modules/three/examples/jsm/utils/BufferGeometryUtils.js`);
-const { Document, NodeIO } = await import(`${TOOLS}/node_modules/@gltf-transform/core/dist/index.js`);
-const { KHRMaterialsEmissiveStrength } = await import(`${TOOLS}/node_modules/@gltf-transform/extensions/dist/index.js`);
+const { Document, NodeIO } = await load('@gltf-transform/core');
+const { KHRMaterialsEmissiveStrength } = await load('@gltf-transform/extensions');
 
 /** texels: one swatch tile covers this many metres */
 const TILE_M = 0.8;
diff --git a/props-kit/_src/textures.mjs b/props-kit/_src/textures.mjs
index df89918..987ae07 100644
--- a/props-kit/_src/textures.mjs
+++ b/props-kit/_src/textures.mjs
@@ -5,7 +5,7 @@
 // slate, and the pack's ONE accent colour — teal (#2f7f7b), the painted crate's.
 import { createRequire } from 'node:module';
 
-const TOOLS = process.env.MESHY_TOOLS ?? '/home/deck/.code/theprototype-app/packs-lane-30c-tools/tools/meshy';
+const TOOLS = process.env.MESHY_TOOLS ?? new URL('../../tools/meshy', import.meta.url).pathname;
 const sharp = createRequire(`${TOOLS}/package.json`)('sharp');
 
 export const TEAL = '#2a6e6a';
diff --git a/tools/architecture-kit/build.mjs b/tools/architecture-kit/build.mjs
index 897add2..d947095 100644
--- a/tools/architecture-kit/build.mjs
+++ b/tools/architecture-kit/build.mjs
@@ -17,6 +17,7 @@ import path from 'node:path';
 import { createRequire } from 'node:module';
 import { fileURLToPath, pathToFileURL } from 'node:url';
 import { TOOLS, kitPost } from './kit-post.mjs';
+import { defightFile } from '../lod/defight.mjs';
 import { kitCut, DERIVE } from './kit-cut.mjs';
 
 const HERE = path.dirname(fileURLToPath(import.meta.url));
@@ -111,6 +112,10 @@ async function buildItem(it) {
 			const next = path.join(tmp, 'cut.glb');
 			report = { ...report, cut: await kitCut(cur, next, typeof it.cut === 'string' ? DERIVE[it.cut](it.cutOpts) : it.cut) };
 			cur = next;
+			// the cut's mortar core / lining meets the post step's surfaces in their planes: settle
+			// z-fights AFTER it (defight in the post step ran before the cut existed) — a rebuild then
+			// reproduces the shipped, settled walls (34-pack-ci: WallStone/WallPlaster byte-identical)
+			await defightFile(cur, cur);
 		}
 		fs.copyFileSync(cur, out);
 		const doc = await io.read(out);
diff --git a/tools/architecture-kit/kit-post.mjs b/tools/architecture-kit/kit-post.mjs
index f8716ac..c6c0c69 100644
--- a/tools/architecture-kit/kit-post.mjs
+++ b/tools/architecture-kit/kit-post.mjs
@@ -1,165 +1,4 @@
-// kit-post: the architecture kit's post step around tools/meshy's meshy-post.
-//
-//   raw Meshy GLB → pre-rotate (Meshy often lays a floor tile or roof slab upright, and
-//   meshy-post only turns about Y) → meshy-post (weld, simplify, stretch to the exact
-//   dims, pivot, 1024² JPEG) → SEAM CLAMP → pack GLB.
-//
-// The seam clamp is what makes pieces snap without gaps: Meshy's ends are never quite
-// planar (a stone sticks out 2 cm, the next one is 3 cm short), so after the stretch
-// every vertex within `eps` of a bbox face named in `clamp` is moved ONTO that face.
-// Two walls placed end to end then share one exact plane at their joint.
-//
-//   node kit-post.mjs <raw.glb> <out.glb> '<job json>'
-//   job = meshy-post's job + { preRotate?: {x?, y?, z?} degrees, clamp?: "x" | "xz" | "xyz" | "x-y" …,
-//         eps?: metres (default 0.04), offset?: [x, y, z] metres applied last,
-//         albedo?: {saturation, brightness, hue} grade of the base colour, dropEmissive?: false to keep it }
-// `clamp` lists axes; a trailing "-y" etc. means "the MIN face of y only" (a floor's bottom).
-import fs from 'node:fs';
-import os from 'node:os';
-import path from 'node:path';
-import { createRequire } from 'node:module';
-import { pathToFileURL } from 'node:url';
-import { defightFile } from '../lod/defight.mjs';
-
-export const TOOLS = process.env.MESHY_TOOLS || '/home/deck/.code/theprototype-app/packs-lane-30c-tools/tools/meshy';
-const req = createRequire(path.join(TOOLS, 'package.json'));
-const load = async (/** @type {string} */ id) => import(pathToFileURL(req.resolve(id)).href);
-
-const { NodeIO } = await load('@gltf-transform/core');
-const { ALL_EXTENSIONS } = await load('@gltf-transform/extensions');
-const { getBounds, transformMesh, prune } = await load('@gltf-transform/functions');
-const { postProcess } = await import(pathToFileURL(path.join(TOOLS, 'lib/post.js')).href);
-const sharp = (await load('sharp')).default;
-
-const io = new NodeIO().registerExtensions(ALL_EXTENSIONS);
-const AX = { x: 0, y: 1, z: 2 };
-
-/** column-major 4x4 rotation about one axis @param {'x'|'y'|'z'} axis @param {number} deg */
-function rot(axis, deg) {
-	const a = (deg * Math.PI) / 180;
-	const c = Math.cos(a);
-	const s = Math.sin(a);
-	if (axis === 'x') return [1, 0, 0, 0, 0, c, s, 0, 0, -s, c, 0, 0, 0, 0, 1];
-	if (axis === 'y') return [c, 0, -s, 0, 0, 1, 0, 0, s, 0, c, 0, 0, 0, 0, 1];
-	return [c, s, 0, 0, -s, c, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1];
-}
-
-/** Parse "xz" / "x-y" / "+y" into [{axis, side}] (side: -1 min, +1 max, 0 both). @param {string} spec */
-export function parseClamp(spec) {
-	const out = [];
-	let sign = 0;
-	for (const ch of spec || '') {
-		if (ch === '-') sign = -1;
-		else if (ch === '+') sign = 1;
-		else if (ch in AX) {
-			out.push({ axis: AX[/** @type {'x'|'y'|'z'} */ (ch)], side: sign });
-			sign = 0;
-		}
-	}
-	return out;
-}
-
-/**
- * Move every vertex within eps of a named bbox face onto it. Returns how many moved.
- * @param {any} doc @param {string} spec @param {number} eps
- */
-export function seamClamp(doc, spec, eps = 0.04) {
-	const faces = parseClamp(spec);
-	if (!faces.length) return 0;
-	const scene = doc.getRoot().getDefaultScene() ?? doc.getRoot().listScenes()[0];
-	const b = getBounds(scene);
-	let moved = 0;
-	const seen = new Set();
-	for (const mesh of doc.getRoot().listMeshes()) {
-		for (const prim of mesh.listPrimitives()) {
-			const pos = prim.getAttribute('POSITION');
-			if (!pos || seen.has(pos)) continue;
-			seen.add(pos);
-			const v = [0, 0, 0];
-			for (let i = 0; i < pos.getCount(); i++) {
-				pos.getElement(i, v);
-				let changed = false;
-				for (const { axis, side } of faces) {
-					if (side <= 0 && v[axis] - b.min[axis] < eps && v[axis] !== b.min[axis]) {
-						v[axis] = b.min[axis];
-						changed = true;
-					}
-					if (side >= 0 && b.max[axis] - v[axis] < eps && v[axis] !== b.max[axis]) {
-						v[axis] = b.max[axis];
-						changed = true;
-					}
-				}
-				if (changed) {
-					pos.setElement(i, v);
-					moved++;
-				}
-			}
-		}
-	}
-	return moved;
-}
-
-/**
- * @param {string} input @param {string} output @param {any} job
- */
-export async function kitPost(input, output, job) {
-	let src = input;
-	const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'kit-post-'));
-	try {
-		if (job.preRotate && Object.values(job.preRotate).some(Boolean)) {
-			const doc = await io.read(input);
-			for (const axis of /** @type {const} */ (['x', 'y', 'z'])) {
-				const deg = job.preRotate[axis];
-				if (!deg) continue;
-				// bake node transforms first would be meshy-post's job; Meshy raws are a
-				// single identity node, so rotating the mesh data is exact here
-				for (const mesh of doc.getRoot().listMeshes()) transformMesh(mesh, /** @type {any} */ (rot(axis, deg)));
-			}
-			src = path.join(tmp, 'rotated.glb');
-			await io.write(src, doc);
-		}
-		const mid = path.join(tmp, 'post.glb');
-		const report = await postProcess(src, mid, job);
-		const doc = await io.read(mid);
-		const moved = seamClamp(doc, job.clamp ?? '', job.eps ?? 0.04);
-		if (job.offset) {
-			// a piece that shares ANOTHER piece's pivot (a window sits 0.95 m up on the wall's
-			// bottom-centre origin, so both place at the same grid point and rotation)
-			const t = [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, job.offset[0] ?? 0, job.offset[1] ?? 0, job.offset[2] ?? 0, 1];
-			for (const mesh of doc.getRoot().listMeshes()) transformMesh(mesh, /** @type {any} */ (t));
-		}
-		let graded = 0;
-		for (const mat of doc.getRoot().listMaterials()) {
-			// architecture never glows: Meshy's refine sometimes ships a faint emissive map
-			// (a glowing floor is baked light in disguise) — drop it outright
-			if (job.dropEmissive !== false) mat.setEmissiveTexture(null).setEmissiveFactor([0, 0, 0]);
-			// a colour GRADE of the albedo, so every piece sits in one palette (Meshy read
-			// "oxblood" as cherry red and "slate" as lavender): sharp.modulate + JPEG
-			const tex = job.albedo && mat.getBaseColorTexture();
-			if (tex) {
-				const { saturation = 1, brightness = 1, hue = 0 } = job.albedo;
-				tex.setImage(new Uint8Array(await sharp(Buffer.from(tex.getImage())).modulate({ saturation, brightness, hue }).jpeg({ quality: 86 }).toBuffer()));
-				tex.setMimeType('image/jpeg');
-				graded++;
-			}
-		}
-		await doc.transform(prune());
-		await io.write(output, doc);
-		// the seam clamp folds relief within eps of a face INTO it: coplanar layers that
-		// z-fight while the camera moves (roadmap 33 K1, the Block). Settle them last.
-		const fight = await defightFile(output, output);
-		return { ...report, output, clamped: moved, defight: { pairs: fight.before, dropped: fight.dropped, pushed: fight.pushed }, graded, bytesOut: fs.statSync(output).size };
-	} finally {
-		fs.rmSync(tmp, { recursive: true, force: true });
-	}
-}
-
-if (process.argv[1] && import.meta.url === pathToFileURL(process.argv[1]).href) {
-	const [input, output, jobJson] = process.argv.slice(2);
-	if (!input || !output) {
-		console.error("usage: kit-post.mjs <raw.glb> <out.glb> '<job json>'");
-		process.exit(2);
-	}
-	const report = await kitPost(input, output, JSON.parse(jobJson || '{}'));
-	console.log(JSON.stringify(report));
-}
+// kit-post: the architecture kit's post step now lives in tools/kit-build/lib/post.mjs — roadmap 34
+// E2, one pack build tool instead of four forks. This file stays so build.mjs and the tests keep
+// their import. CLI: node tools/kit-build/kit-build.mjs post <raw.glb> <out.glb> '<job json>'
+export { TOOLS, kitPost, parseClamp, seamClamp } from '../kit-build/lib/post.mjs';
diff --git a/tools/kit-build/README.md b/tools/kit-build/README.md
new file mode 100644
index 0000000..40fe981
--- /dev/null
+++ b/tools/kit-build/README.md
@@ -0,0 +1,99 @@
+# tools/kit-build — the one pack build tool, and the pack CI
+
+Every kit used to carry its own copy of the post-processing (architecture, sci-fi and town had a
+`kit-post.mjs` each; nature, props and interior their own grade / emissive / flat-for-sync
+helpers). They now share this tool. A kit keeps only its **recipe** — which Meshy raw, kitbash or
+procedural piece makes each item — and everything after it is here.
+
+```
+cd tools/meshy && npm ci                              # once: the deps every pack tool uses
+node tools/kit-build/kit-build.mjs <command> …
+```
+
+| command | what it does |
+|---|---|
+| `build <pack> [--only A,B] [--no-thumbs]` | the pack's recipe → `pass --write` → judged defight → LOD1/LOD2 → thumbnails → `check` |
+| `post <raw.glb> <out.glb> '<job>'` | the one post step on a Meshy raw: pre-rotate, meshy-post (weld, **decimate to `targetTris`**, stretch to `dims`, pivot, textures to the cap as JPEG), seam clamp, offset, **emissive policy** + albedo grade, recolor, glow mask, defight (`lib/post.mjs` documents the job) |
+| `pass <pack…\|--all> [--write]` | on the SHIPPED LOD0s, from `packs.json`: emissive policy, **texture cap per pack**, PNG → JPEG for an opaque file over the 5 MiB share cap, **decimate to the category budget**. Dry run unless `--write`; a compliant file is never rewritten |
+| `lod <pack>` | `tools/lod`: judged defight of LOD0s, then LOD1/LOD2 files + each row's `lods` (P1), then `--check` |
+| `thumbs <pack> [--only A,B]` | renders each row's screenshot (512², transparent, yaw 35°) |
+| `flicker <pack…\|--all> [--record]` | the static z-fight probe; `--record` RENDERS every file over the limit (headless) and writes `flicker-baseline.json` |
+| `report [pack…] [--md f] [--json f]` | the **budget report**: per item tris vs budget, MiB, largest texture, LOD triangles, z-fight cm² |
+| `check [pack…] [--summary f] [--json f]` | **the CI** — exit 1 on any error that `allow.json` does not list |
+
+The recipes `build` runs: `tools/architecture-kit/build.mjs`, `tools/scifi-kit/build.mjs`,
+`tools/town-kit/build.mjs`, `tools/interactive-kit/build.mjs`, `nature-kit/build/finalize.mjs`,
+`props-kit/_src/build.mjs`, `interior-kit/_src/build.mjs` (they read the staged Meshy raws under
+`~/.code/lanes-30/meshy/staging/`; nothing here spends credits).
+
+**Byte-stable.** When the forks were folded in (roadmap 34), the old and the new code rebuilt the
+architecture, nature, props, interior and sci-fi kits from the same raws: 159 / 159 GLBs
+byte-identical. `pass --all` on main changes exactly one file (default/SvelteRune, see below).
+
+## The checks (`check`, run on every packs PR)
+
+| check | rule |
+|---|---|
+| index | `index.json` rows: name, title, exactly one of value / zip, attribution, copyright, license, https source; files exist; every pack has a policy in `packs.json` |
+| manifest | each model list: row shape incl. **`lods`** (P1: files beside LOD0, ratios in (0, 1], finest first) and **`behavior`** (P2: type, clip, trigger, autoplay only for `loop`, closeClip only for door/toggle, no unknown keys — core silently normalises a typo, the CI refuses it); unique names; no orphan GLBs (warn) |
+| size | every GLB ≤ 5 MiB (the share cap — bigger never reaches a peer); warn > 2 MiB |
+| tris | LOD0's drawn triangles ≤ the item's category budget |
+| textures | largest texture side ≤ the pack's cap |
+| emissive | a pack whose policy is `none` has nothing that glows; an emissive map under a black factor warns |
+| scale | the bbox is in metres: largest extent ≥ 5 cm and ≤ the category's maximum |
+| pivot | the origin is where the item's pivot rule says (below) |
+| lods | items over 2 000 triangles ship LOD files; each exists, has fewer triangles than LOD0, its `ratio` is the measured one (± 0.05), keeps LOD0's mesh-node names (core swaps BY NAME) and its clips |
+| behavior | the clips a behavior names exist in the GLB and in every LOD file |
+| flicker | the static z-fight probe (`tools/lod/coplanar.mjs`: coplanar triangle pairs, both facings when double-sided) ≤ 1 cm² — or at most the file's recorded baseline |
+| thumb | the row's screenshot exists, decodes, ≥ 64 px |
+
+### Policy: `packs.json`
+
+`categories` give the triangle budget and largest extent (tile 2 500 · prop 6 000 · modular 6 500 ·
+functional 7 000 · hero 8 000 · set 12 000 · tree 15 000 · legacy 25 000). `packs` give each pack's
+`textureCap`, `emissive` (`none` | `allowed`), default `category` and `pivot`, and per-item
+overrides. **A new pack needs a row here** — the check says so.
+
+Pivot rules: `bottom-center` (default) · `bottom-center-back` (a tapestry, a torch: back on the
+origin) · `top-center` (hangs: a chandelier, a fan) · `wall-pivot` (shares the wall's bottom-centre
+origin and starts above the floor: a window) · `wall-face` (origin on the wall line, the piece on
+the wall's face: interior trims, a wall screen) · `foot` (stands on its origin, which is under the
+piece but not its middle: a signpost's post) · `hinge` (origin within 5 cm of the piece: a lever
+handle) · `any` (legacy packs that keep their source scene's coordinates).
+
+### Accepted failures: `allow.json`
+
+`{pack, item ('*' = all), check, file?, reason}`. Every entry carries the reason it is accepted; an
+entry that matches nothing is reported so it gets removed once the item is fixed. Today: 15 items
+`tools/lod` builds no level for (its visual gate refuses every candidate — foliage, straw and fine
+detail need impostor levels, roadmap-33 F2) and nature-kit's PondSet render flicker.
+
+### The z-fight baseline: `flicker-baseline.json`
+
+The static probe over-counts: a coplanar pair hidden inside a piece, or one whose two layers carry
+the same texels, never shows — which is why 33-pack-fix-lod only rewrote a file when a RENDER
+flickered clearly less. A file over the static limit therefore passes only if it was rendered
+(`tools/lod/judge.mjs` flicker: 512², 12 orbit poses, micro-triplets) at ≤ 400 px and recorded with
+its overlap; the CI holds it to that area (+2 %). After `defight-all` or a rebuild:
+
+```
+node tools/kit-build/kit-build.mjs flicker <pack> --record   # refuses (exit 1) a file over 400 px
+```
+
+## Making the check required (repo admin)
+
+The workflow is `.github/workflows/pack-checks.yml`, job **`pack-checks`**. In GitHub: Settings →
+Branches → branch protection rule for `main` (or Rules → Rulesets) → *Require status checks to pass*
+→ add `pack-checks`. Or:
+
+```
+gh api -X PUT repos/theprototype-app/packs/branches/main/protection --input - <<'JSON'
+{"required_status_checks": {"strict": false, "contexts": ["pack-checks"]},
+ "enforce_admins": false, "required_pull_request_reviews": null, "restrictions": null}
+JSON
+```
+
+## Tests
+
+`node --test tools/kit-build/test/*.test.mjs` — a fixture pack that passes every check, then each
+check shown red on the one thing it exists to catch (and `pass` fixing it, byte-stable after).
diff --git a/tools/kit-build/allow.json b/tools/kit-build/allow.json
new file mode 100644
index 0000000..cf650d0
--- /dev/null
+++ b/tools/kit-build/allow.json
@@ -0,0 +1,102 @@
+{
+	"note": "Known, accepted failures of `kit-build check` — each with the reason it is accepted. {pack, item ('*' = every item), check, file? (one file only), reason}. An entry that matches nothing is reported, so remove it once the item is fixed.",
+	"allow": [
+		{
+			"pack": "nature-kit",
+			"item": "Birch",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: no level reaches <= 80 % within the error caps (best 1 / 1) — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "nature-kit",
+			"item": "Palm",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: no level reaches <= 80 % within the error caps (best 1 / 1) — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "nature-kit",
+			"item": "Bush",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: best 0.86 / 0.83 of LOD0 — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "nature-kit",
+			"item": "BushAutumn",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: best 0.86 / 0.83 of LOD0 — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "nature-kit",
+			"item": "Fern",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: best 0.9 / 1 of LOD0 — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "nature-kit",
+			"item": "FlowerPatch",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: best 0.97 / 0.97 of LOD0 — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "props-kit",
+			"item": "PottedPlant",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: best 1 / 1 of LOD0 — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "scifi-kit",
+			"item": "ServerRack",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: best 0.82 / 0.81 of LOD0 — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "scifi-kit",
+			"item": "PlantPod",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: best 0.9 / 0.9 of LOD0 — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "interior-kit",
+			"item": "Plant",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: best 1 / 1 of LOD0 — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "interior-kit",
+			"item": "Chandelier",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: best 1 / 1 of LOD0 — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "town-kit",
+			"item": "FlowerBox",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: best 0.82 / 0.82 of LOD0 — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "town-kit",
+			"item": "FlowerBoxLong",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: best 0.82 / 0.82 of LOD0 — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "town-kit",
+			"item": "HayStack",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: best 0.85 / 0.84 of LOD0 — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "default",
+			"item": "SvelteRune",
+			"check": "lods",
+			"reason": "tools/lod (33-pack-fix-lod) builds no level: best 0.88 / 0.82 of LOD0 (the starter model, 2000-tri floor) — the visual gate refuses every candidate (foliage / straw / fine detail needs impostor levels, roadmap-33 F2); core's automatic runtime LOD still applies"
+		},
+		{
+			"pack": "nature-kit",
+			"item": "PondSet",
+			"check": "flicker",
+			"file": "nature-kit/PondSet/glTF-Binary/PondSet.glb",
+			"reason": "render probe 404 px (> the 400 px recording limit) — the same 404 px 33-pack-fix-lod measured; none of defight's candidates flickers clearly less (best 403 px), and the roadmap-33 in-app scan passed it under the patch limit. The kitbash's reeds and pond edge, not a fixable coplanar layer; re-judge if the pond is rebuilt"
+		}
+	]
+}
diff --git a/tools/kit-build/flicker-baseline.json b/tools/kit-build/flicker-baseline.json
new file mode 100644
index 0000000..48bced4
--- /dev/null
+++ b/tools/kit-build/flicker-baseline.json
@@ -0,0 +1,714 @@
+{
+ "note": "The static z-fight probe's accepted files (kit-build check: a file over 1 cm² of coplanar overlap passes only at or under its recorded area). Each was RENDERED (tools/lod/judge.mjs flicker: 512², 12 orbit poses) and flickers at most 400 px; px = that measurement. Written by: node tools/kit-build/kit-build.mjs flicker <pack> --record",
+ "limitPx": 400,
+ "files": {
+  "arcane-kit/AlchemyTable/glTF-Binary/alchemy-table.glb": {
+   "cm2": 103.09,
+   "pairs": 5,
+   "px": 50,
+   "why": "not in defight-report.json (built before tools/lod or outside it)"
+  },
+  "arcane-kit/AlchemyTable/glTF-Binary/alchemy-table.lod1.glb": {
+   "cm2": 101.3,
+   "pairs": 4,
+   "px": 29,
+   "why": "a level of AlchemyTable: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "arcane-kit/AlchemyTable/glTF-Binary/alchemy-table.lod2.glb": {
+   "cm2": 101.3,
+   "pairs": 4,
+   "px": 35,
+   "why": "a level of AlchemyTable: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "arcane-kit/PotionShelf/glTF-Binary/potion-shelf.glb": {
+   "cm2": 9.99,
+   "pairs": 6,
+   "px": 13,
+   "why": "not in defight-report.json (built before tools/lod or outside it)"
+  },
+  "arcane-kit/PotionShelf/glTF-Binary/potion-shelf.lod1.glb": {
+   "cm2": 9.99,
+   "pairs": 6,
+   "px": 20,
+   "why": "a level of PotionShelf: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "arcane-kit/RuneRug/glTF-Binary/rune-rug.glb": {
+   "cm2": 2.31,
+   "pairs": 6,
+   "px": 25,
+   "why": "not in defight-report.json (built before tools/lod or outside it)"
+  },
+  "arcane-kit/RuneRug/glTF-Binary/rune-rug.lod1.glb": {
+   "cm2": 1.99,
+   "pairs": 4,
+   "px": 30,
+   "why": "a level of RuneRug: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "arcane-kit/Telescope/glTF-Binary/telescope.lod1.glb": {
+   "cm2": 3.39,
+   "pairs": 6,
+   "px": 68,
+   "why": "a level of Telescope: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Arch/glTF-Binary/arch.lod1.glb": {
+   "cm2": 7.9,
+   "pairs": 5,
+   "px": 20,
+   "why": "a level of Arch: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Block/glTF-Binary/block.lod1.glb": {
+   "cm2": 11.57,
+   "pairs": 7,
+   "px": 276,
+   "why": "a level of Block: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Chimney/glTF-Binary/chimney.glb": {
+   "cm2": 1023.53,
+   "pairs": 24,
+   "px": 23,
+   "why": "defight left it: no candidate flickers clearly less (render 23 → 23 px)"
+  },
+  "architecture-kit/Chimney/glTF-Binary/chimney.lod1.glb": {
+   "cm2": 483.67,
+   "pairs": 14,
+   "px": 19,
+   "why": "a level of Chimney: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Column/glTF-Binary/column.glb": {
+   "cm2": 63.84,
+   "pairs": 15,
+   "px": 3,
+   "why": "defight left it: no candidate flickers clearly less (render 3 → 3 px)"
+  },
+  "architecture-kit/Column/glTF-Binary/column.lod1.glb": {
+   "cm2": 18.23,
+   "pairs": 3,
+   "px": 4,
+   "why": "a level of Column: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Column/glTF-Binary/column.lod2.glb": {
+   "cm2": 1.72,
+   "pairs": 2,
+   "px": 6,
+   "why": "a level of Column: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Door/glTF-Binary/door.glb": {
+   "cm2": 18.21,
+   "pairs": 7,
+   "px": 16,
+   "why": "defight left it: no candidate flickers clearly less (render 16 → 16 px)"
+  },
+  "architecture-kit/Door/glTF-Binary/door.lod1.glb": {
+   "cm2": 13.92,
+   "pairs": 7,
+   "px": 19,
+   "why": "a level of Door: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Fence/glTF-Binary/fence.glb": {
+   "cm2": 15.32,
+   "pairs": 19,
+   "px": 200,
+   "why": "defight left it: no candidate flickers clearly less (render 200 → 200 px)"
+  },
+  "architecture-kit/Fence/glTF-Binary/fence.lod1.glb": {
+   "cm2": 15.2,
+   "pairs": 17,
+   "px": 207,
+   "why": "a level of Fence: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Fence/glTF-Binary/fence.lod2.glb": {
+   "cm2": 2.43,
+   "pairs": 5,
+   "px": 42,
+   "why": "a level of Fence: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/FloorSlate/glTF-Binary/floor-slate.glb": {
+   "cm2": 577.97,
+   "pairs": 16,
+   "px": 87,
+   "why": "defight left it: no candidate flickers clearly less (render 87 → 87 px)"
+  },
+  "architecture-kit/FloorStone/glTF-Binary/floor-stone.glb": {
+   "cm2": 577.97,
+   "pairs": 16,
+   "px": 48,
+   "why": "defight left it: no candidate flickers clearly less (render 48 → 48 px)"
+  },
+  "architecture-kit/FloorWood/glTF-Binary/floor-wood.glb": {
+   "cm2": 577.97,
+   "pairs": 16,
+   "px": 45,
+   "why": "defight left it: no candidate flickers clearly less (render 45 → 45 px)"
+  },
+  "architecture-kit/Gate/glTF-Binary/gate.glb": {
+   "cm2": 146.21,
+   "pairs": 34,
+   "px": 37,
+   "why": "defight left it: no candidate flickers clearly less (render 37 → 35 px)"
+  },
+  "architecture-kit/Gate/glTF-Binary/gate.lod1.glb": {
+   "cm2": 144.73,
+   "pairs": 28,
+   "px": 37,
+   "why": "a level of Gate: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Gate/glTF-Binary/gate.lod2.glb": {
+   "cm2": 139.82,
+   "pairs": 25,
+   "px": 33,
+   "why": "a level of Gate: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Pillar/glTF-Binary/pillar.glb": {
+   "cm2": 551.59,
+   "pairs": 24,
+   "px": 14,
+   "why": "defight left it: no candidate flickers clearly less (render 14 → 13 px)"
+  },
+  "architecture-kit/Pillar/glTF-Binary/pillar.lod1.glb": {
+   "cm2": 131.66,
+   "pairs": 6,
+   "px": 13,
+   "why": "a level of Pillar: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Ramp/glTF-Binary/ramp.lod1.glb": {
+   "cm2": 1.85,
+   "pairs": 1,
+   "px": 176,
+   "why": "a level of Ramp: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Ramp/glTF-Binary/ramp.lod2.glb": {
+   "cm2": 1.85,
+   "pairs": 1,
+   "px": 199,
+   "why": "a level of Ramp: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/RoofSlope/glTF-Binary/roof-slope.glb": {
+   "cm2": 1040.06,
+   "pairs": 8,
+   "px": 296,
+   "why": "defight (surface) settled the visible layers; the rest are hidden"
+  },
+  "architecture-kit/RoofSlope/glTF-Binary/roof-slope.lod1.glb": {
+   "cm2": 732.02,
+   "pairs": 6,
+   "px": 185,
+   "why": "a level of RoofSlope: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Stairs/glTF-Binary/stairs.glb": {
+   "cm2": 382.66,
+   "pairs": 139,
+   "px": 96,
+   "why": "defight (drop-only) settled the visible layers; the rest are hidden"
+  },
+  "architecture-kit/Stairs/glTF-Binary/stairs.lod1.glb": {
+   "cm2": 186.88,
+   "pairs": 53,
+   "px": 52,
+   "why": "a level of Stairs: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Stairs/glTF-Binary/stairs.lod2.glb": {
+   "cm2": 118.63,
+   "pairs": 25,
+   "px": 33,
+   "why": "a level of Stairs: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/StairsWood/glTF-Binary/stairs-wood.glb": {
+   "cm2": 455.88,
+   "pairs": 151,
+   "px": 95,
+   "why": "defight left it: no candidate flickers clearly less (render 95 → 79 px)"
+  },
+  "architecture-kit/StairsWood/glTF-Binary/stairs-wood.lod1.glb": {
+   "cm2": 180.01,
+   "pairs": 53,
+   "px": 55,
+   "why": "a level of StairsWood: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/StairsWood/glTF-Binary/stairs-wood.lod2.glb": {
+   "cm2": 118.29,
+   "pairs": 21,
+   "px": 18,
+   "why": "a level of StairsWood: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "architecture-kit/Tower/glTF-Binary/tower.glb": {
+   "cm2": 1329.54,
+   "pairs": 313,
+   "px": 78,
+   "why": "defight left it: no candidate flickers clearly less (render 78 → 77 px)"
+  },
+  "architecture-kit/Tower/glTF-Binary/tower.lod1.glb": {
+   "cm2": 530.42,
+   "pairs": 79,
+   "px": 68,
+   "why": "a level of Tower: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "cube_diorama/Desk/glTF-Binary/desk.glb": {
+   "cm2": 25.51,
+   "pairs": 5,
+   "px": 4,
+   "why": "defight left it: no candidate flickers clearly less (render 4 → 5 px)"
+  },
+  "cube_diorama/Dresser/glTF-Binary/dresser.glb": {
+   "cm2": 5009.29,
+   "pairs": 16,
+   "px": 7,
+   "why": "defight left it: no candidate flickers clearly less (render 7 → 8 px)"
+  },
+  "cube_diorama/Dresser/glTF-Binary/dresser.lod1.glb": {
+   "cm2": 5105.64,
+   "pairs": 20,
+   "px": 6,
+   "why": "a level of Dresser: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "cube_diorama/Dresser/glTF-Binary/dresser.lod2.glb": {
+   "cm2": 5060.6,
+   "pairs": 18,
+   "px": 9,
+   "why": "a level of Dresser: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "cube_diorama/Window/glTF-Binary/window.glb": {
+   "cm2": 136.03,
+   "pairs": 22,
+   "px": 15,
+   "why": "defight left it: no candidate flickers clearly less (render 15 → 15 px)"
+  },
+  "interactive-kit/DoorStudded/glTF-Binary/door-studded.glb": {
+   "cm2": 1953.37,
+   "pairs": 32,
+   "px": 50,
+   "why": "not in defight-report.json (built before tools/lod or outside it)"
+  },
+  "interactive-kit/DoorStudded/glTF-Binary/door-studded.lod1.glb": {
+   "cm2": 1961.41,
+   "pairs": 31,
+   "px": 55,
+   "why": "a level of DoorStudded: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "interactive-kit/DoorStudded/glTF-Binary/door-studded.lod2.glb": {
+   "cm2": 1846.21,
+   "pairs": 16,
+   "px": 69,
+   "why": "a level of DoorStudded: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "interactive-kit/DoorWood/glTF-Binary/door-wood.lod1.glb": {
+   "cm2": 146.98,
+   "pairs": 4,
+   "px": 31,
+   "why": "a level of DoorWood: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "interactive-kit/Drawers/glTF-Binary/drawers.lod2.glb": {
+   "cm2": 243.33,
+   "pairs": 1,
+   "px": 41,
+   "why": "a level of Drawers: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "interactive-kit/IronGate/glTF-Binary/iron-gate.lod2.glb": {
+   "cm2": 7.57,
+   "pairs": 1,
+   "px": 174,
+   "why": "a level of IronGate: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "interactive-kit/Portcullis/glTF-Binary/portcullis.glb": {
+   "cm2": 3624.92,
+   "pairs": 79,
+   "px": 226,
+   "why": "not in defight-report.json (built before tools/lod or outside it)"
+  },
+  "interactive-kit/Portcullis/glTF-Binary/portcullis.lod1.glb": {
+   "cm2": 3560.37,
+   "pairs": 49,
+   "px": 230,
+   "why": "a level of Portcullis: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "interactive-kit/Shutters/glTF-Binary/shutters.lod1.glb": {
+   "cm2": 1.05,
+   "pairs": 2,
+   "px": 77,
+   "why": "a level of Shutters: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "nature-kit/Birch/glTF-Binary/Birch.glb": {
+   "cm2": 4.41,
+   "pairs": 1,
+   "px": 25,
+   "why": "defight left it: no candidate flickers clearly less (render 25 → 25 px)"
+  },
+  "nature-kit/Bridge/glTF-Binary/Bridge.lod1.glb": {
+   "cm2": 2.46,
+   "pairs": 3,
+   "px": 37,
+   "why": "a level of Bridge: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "nature-kit/Bridge/glTF-Binary/Bridge.lod2.glb": {
+   "cm2": 2.46,
+   "pairs": 3,
+   "px": 33,
+   "why": "a level of Bridge: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "nature-kit/Bush/glTF-Binary/Bush.glb": {
+   "cm2": 40.57,
+   "pairs": 1,
+   "px": 41,
+   "why": "defight left it: no candidate flickers clearly less (render 41 → 40 px)"
+  },
+  "nature-kit/BushAutumn/glTF-Binary/BushAutumn.glb": {
+   "cm2": 40.57,
+   "pairs": 1,
+   "px": 39,
+   "why": "defight left it: no candidate flickers clearly less (render 39 → 38 px)"
+  },
+  "nature-kit/Fern/glTF-Binary/Fern.glb": {
+   "cm2": 136.42,
+   "pairs": 18,
+   "px": 67,
+   "why": "defight left it: no candidate flickers clearly less (render 67 → 66 px)"
+  },
+  "nature-kit/FlowerPatch/glTF-Binary/FlowerPatch.glb": {
+   "cm2": 79.03,
+   "pairs": 66,
+   "px": 238,
+   "why": "defight left it: no candidate flickers clearly less (render 238 → 238 px)"
+  },
+  "nature-kit/Flowers/glTF-Binary/Flowers.glb": {
+   "cm2": 29.84,
+   "pairs": 20,
+   "px": 18,
+   "why": "defight left it: no candidate flickers clearly less (render 18 → 18 px)"
+  },
+  "nature-kit/FlowersViolet/glTF-Binary/FlowersViolet.glb": {
+   "cm2": 29.84,
+   "pairs": 20,
+   "px": 21,
+   "why": "defight left it: no candidate flickers clearly less (render 21 → 20 px)"
+  },
+  "nature-kit/Log/glTF-Binary/Log.lod1.glb": {
+   "cm2": 3.18,
+   "pairs": 2,
+   "px": 37,
+   "why": "a level of Log: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "nature-kit/Pine/glTF-Binary/Pine.glb": {
+   "cm2": 17.75,
+   "pairs": 3,
+   "px": 31,
+   "why": "defight left it: no candidate flickers clearly less (render 31 → 31 px)"
+  },
+  "nature-kit/PondSet/glTF-Binary/PondSet.lod1.glb": {
+   "cm2": 11.54,
+   "pairs": 3,
+   "px": 300,
+   "why": "a level of PondSet: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "nature-kit/Reeds/glTF-Binary/Reeds.glb": {
+   "cm2": 134.8,
+   "pairs": 8,
+   "px": 62,
+   "why": "defight left it: no candidate flickers clearly less (render 62 → 47 px)"
+  },
+  "props-kit/Bed/glTF-Binary/bed.glb": {
+   "cm2": 2437.17,
+   "pairs": 48,
+   "px": 48,
+   "why": "defight left it: no candidate flickers clearly less (render 48 → 48 px)"
+  },
+  "props-kit/Bed/glTF-Binary/bed.lod1.glb": {
+   "cm2": 1901.46,
+   "pairs": 33,
+   "px": 25,
+   "why": "a level of Bed: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "props-kit/Bed/glTF-Binary/bed.lod2.glb": {
+   "cm2": 1707.81,
+   "pairs": 31,
+   "px": 22,
+   "why": "a level of Bed: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "props-kit/Bench/glTF-Binary/bench.glb": {
+   "cm2": 298.04,
+   "pairs": 52,
+   "px": 113,
+   "why": "defight left it: no candidate flickers clearly less (render 113 → 105 px)"
+  },
+  "props-kit/Bench/glTF-Binary/bench.lod1.glb": {
+   "cm2": 313.22,
+   "pairs": 30,
+   "px": 74,
+   "why": "a level of Bench: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "props-kit/Bookcase/glTF-Binary/bookcase.glb": {
+   "cm2": 4441.45,
+   "pairs": 23,
+   "px": 29,
+   "why": "defight left it: no candidate flickers clearly less (render 29 → 29 px)"
+  },
+  "props-kit/Bookcase/glTF-Binary/bookcase.lod1.glb": {
+   "cm2": 2581.66,
+   "pairs": 6,
+   "px": 32,
+   "why": "a level of Bookcase: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "props-kit/Candles/glTF-Binary/candles.glb": {
+   "cm2": 5.94,
+   "pairs": 20,
+   "px": 13,
+   "why": "defight left it: no candidate flickers clearly less (render 13 → 14 px)"
+  },
+  "props-kit/Candles/glTF-Binary/candles.lod1.glb": {
+   "cm2": 4.29,
+   "pairs": 6,
+   "px": 12,
+   "why": "a level of Candles: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "props-kit/Chest/glTF-Binary/chest.glb": {
+   "cm2": 210.01,
+   "pairs": 18,
+   "px": 57,
+   "why": "defight left it: no candidate flickers clearly less (render 57 → 46 px)"
+  },
+  "props-kit/Chest/glTF-Binary/chest.lod1.glb": {
+   "cm2": 209.65,
+   "pairs": 16,
+   "px": 53,
+   "why": "a level of Chest: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "props-kit/Chest/glTF-Binary/chest.lod2.glb": {
+   "cm2": 148.74,
+   "pairs": 12,
+   "px": 29,
+   "why": "a level of Chest: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "props-kit/Hatch/glTF-Binary/hatch.glb": {
+   "cm2": 33.37,
+   "pairs": 12,
+   "px": 24,
+   "why": "defight left it: no candidate flickers clearly less (render 22 → 24 px)"
+  },
+  "props-kit/Ladder/glTF-Binary/ladder.glb": {
+   "cm2": 70,
+   "pairs": 8,
+   "px": 2,
+   "why": "defight left it: no candidate flickers clearly less (render 2 → 2 px)"
+  },
+  "props-kit/Lantern/glTF-Binary/lantern.glb": {
+   "cm2": 2.66,
+   "pairs": 6,
+   "px": 33,
+   "why": "defight (drop-only) settled the visible layers; the rest are hidden"
+  },
+  "props-kit/Lantern/glTF-Binary/lantern.lod1.glb": {
+   "cm2": 2.03,
+   "pairs": 3,
+   "px": 21,
+   "why": "a level of Lantern: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "props-kit/PottedPlant/glTF-Binary/potted-plant.glb": {
+   "cm2": 53.6,
+   "pairs": 19,
+   "px": 28,
+   "why": "defight left it: no candidate flickers clearly less (render 28 → 23 px)"
+  },
+  "props-kit/Table/glTF-Binary/table.glb": {
+   "cm2": 249.04,
+   "pairs": 108,
+   "px": 77,
+   "why": "defight left it: no candidate flickers clearly less (render 77 → 66 px)"
+  },
+  "props-kit/Table/glTF-Binary/table.lod1.glb": {
+   "cm2": 240.54,
+   "pairs": 18,
+   "px": 64,
+   "why": "a level of Table: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "props-kit/WallTorch/glTF-Binary/wall-torch.glb": {
+   "cm2": 4.07,
+   "pairs": 8,
+   "px": 8,
+   "why": "defight left it: no candidate flickers clearly less (render 8 → 5 px)"
+  },
+  "props-kit/WallTorch/glTF-Binary/wall-torch.lod1.glb": {
+   "cm2": 2.88,
+   "pairs": 4,
+   "px": 9,
+   "why": "a level of WallTorch: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "props-kit/WallTorch/glTF-Binary/wall-torch.lod2.glb": {
+   "cm2": 2.88,
+   "pairs": 4,
+   "px": 5,
+   "why": "a level of WallTorch: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "props-kit/Well/glTF-Binary/well.glb": {
+   "cm2": 122.18,
+   "pairs": 3,
+   "px": 45,
+   "why": "defight left it: no candidate flickers clearly less (render 45 → 45 px)"
+  },
+  "props-kit/Well/glTF-Binary/well.lod1.glb": {
+   "cm2": 128.78,
+   "pairs": 1,
+   "px": 39,
+   "why": "a level of Well: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "props-kit/Workbench/glTF-Binary/workbench.glb": {
+   "cm2": 55.93,
+   "pairs": 16,
+   "px": 69,
+   "why": "defight left it: no candidate flickers clearly less (render 69 → 69 px)"
+  },
+  "props-kit/Workbench/glTF-Binary/workbench.lod1.glb": {
+   "cm2": 54.54,
+   "pairs": 9,
+   "px": 56,
+   "why": "a level of Workbench: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "props-kit/Workbench/glTF-Binary/workbench.lod2.glb": {
+   "cm2": 53.01,
+   "pairs": 7,
+   "px": 60,
+   "why": "a level of Workbench: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "scifi-kit/Chair/glTF-Binary/chair.glb": {
+   "cm2": 75.16,
+   "pairs": 3,
+   "px": 25,
+   "why": "defight left it: no candidate flickers clearly less (render 25 → 25 px)"
+  },
+  "scifi-kit/Chair/glTF-Binary/chair.lod1.glb": {
+   "cm2": 62.35,
+   "pairs": 2,
+   "px": 27,
+   "why": "a level of Chair: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "scifi-kit/CornerPost/glTF-Binary/corner-post.glb": {
+   "cm2": 5889.88,
+   "pairs": 217,
+   "px": 7,
+   "why": "defight left it: no candidate flickers clearly less (render 7 → 7 px)"
+  },
+  "scifi-kit/CornerPost/glTF-Binary/corner-post.lod1.glb": {
+   "cm2": 1116.33,
+   "pairs": 112,
+   "px": 6,
+   "why": "a level of CornerPost: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "scifi-kit/Desk/glTF-Binary/desk.glb": {
+   "cm2": 79.92,
+   "pairs": 11,
+   "px": 71,
+   "why": "defight left it: no candidate flickers clearly less (render 71 → 68 px)"
+  },
+  "scifi-kit/Desk/glTF-Binary/desk.lod1.glb": {
+   "cm2": 1.76,
+   "pairs": 3,
+   "px": 105,
+   "why": "a level of Desk: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "scifi-kit/Desk/glTF-Binary/desk.lod2.glb": {
+   "cm2": 1.32,
+   "pairs": 1,
+   "px": 113,
+   "why": "a level of Desk: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "scifi-kit/Drone/glTF-Binary/drone.lod1.glb": {
+   "cm2": 1.38,
+   "pairs": 1,
+   "px": 16,
+   "why": "a level of Drone: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "scifi-kit/FloorPlate/glTF-Binary/floor-plate.glb": {
+   "cm2": 186402.81,
+   "pairs": 1243,
+   "px": 86,
+   "why": "defight left it: no candidate flickers clearly less (render 86 → 79 px)"
+  },
+  "scifi-kit/FloorPlate/glTF-Binary/floor-plate.lod1.glb": {
+   "cm2": 1274.29,
+   "pairs": 22,
+   "px": 98,
+   "why": "a level of FloorPlate: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "scifi-kit/FloorPlate/glTF-Binary/floor-plate.lod2.glb": {
+   "cm2": 1424.03,
+   "pairs": 19,
+   "px": 74,
+   "why": "a level of FloorPlate: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "scifi-kit/Lamp/glTF-Binary/lamp.glb": {
+   "cm2": 27.55,
+   "pairs": 32,
+   "px": 5,
+   "why": "defight left it: no candidate flickers clearly less (render 3 → 3 px)"
+  },
+  "scifi-kit/PlantPod/glTF-Binary/plant-pod.glb": {
+   "cm2": 112.98,
+   "pairs": 9,
+   "px": 95,
+   "why": "defight left it: no candidate flickers clearly less (render 95 → 92 px)"
+  },
+  "scifi-kit/Railing/glTF-Binary/railing.glb": {
+   "cm2": 2.13,
+   "pairs": 8,
+   "px": 13,
+   "why": "defight left it: no candidate flickers clearly less (render 13 → 14 px)"
+  },
+  "scifi-kit/Ramp/glTF-Binary/ramp.glb": {
+   "cm2": 176,
+   "pairs": 4,
+   "px": 24,
+   "why": "defight left it: no candidate flickers clearly less (render 25 → 24 px)"
+  },
+  "scifi-kit/ServerRack/glTF-Binary/server-rack.glb": {
+   "cm2": 7561.23,
+   "pairs": 43,
+   "px": 35,
+   "why": "defight left it: no candidate flickers clearly less (render 35 → 28 px)"
+  },
+  "scifi-kit/SlidingDoor/glTF-Binary/sliding-door.glb": {
+   "cm2": 47.29,
+   "pairs": 27,
+   "px": 61,
+   "why": "defight left it: no candidate flickers clearly less (render 61 → 58 px)"
+  },
+  "scifi-kit/SlidingDoor/glTF-Binary/sliding-door.lod1.glb": {
+   "cm2": 47.05,
+   "pairs": 22,
+   "px": 42,
+   "why": "a level of SlidingDoor: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "scifi-kit/SlidingDoor/glTF-Binary/sliding-door.lod2.glb": {
+   "cm2": 36.87,
+   "pairs": 18,
+   "px": 40,
+   "why": "a level of SlidingDoor: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "scifi-kit/Stairs/glTF-Binary/stairs.lod2.glb": {
+   "cm2": 6.21,
+   "pairs": 8,
+   "px": 245,
+   "why": "a level of Stairs: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "scifi-kit/TeleportPad/glTF-Binary/teleport-pad.lod2.glb": {
+   "cm2": 3.62,
+   "pairs": 3,
+   "px": 12,
+   "why": "a level of TeleportPad: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "scifi-kit/Vent/glTF-Binary/vent.glb": {
+   "cm2": 578.44,
+   "pairs": 75,
+   "px": 21,
+   "why": "defight left it: no candidate flickers clearly less (render 21 → 21 px)"
+  },
+  "town-kit/ClockTowerTop/glTF-Binary/clock-tower-top.lod2.glb": {
+   "cm2": 1614.25,
+   "pairs": 1,
+   "px": 34,
+   "why": "a level of ClockTowerTop: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  },
+  "town-kit/MarketStall/glTF-Binary/market-stall.lod2.glb": {
+   "cm2": 26.39,
+   "pairs": 1,
+   "px": 53,
+   "why": "a level of MarketStall: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)"
+  }
+ }
+}
diff --git a/tools/kit-build/kit-build.mjs b/tools/kit-build/kit-build.mjs
new file mode 100644
index 0000000..91a9f29
--- /dev/null
+++ b/tools/kit-build/kit-build.mjs
@@ -0,0 +1,127 @@
+#!/usr/bin/env node
+// kit-build — THE pack build tool (roadmap 34 E2). One command line for every step a pack goes
+// through after its recipe made the GLBs; the per-kit forks of these steps are gone (see README.md).
+//
+//   node tools/kit-build/kit-build.mjs <command> …       (deps: cd tools/meshy && npm ci)
+//
+//   build  <pack> [--only A,B] [--no-thumbs]   run the pack's recipe, then lod + thumbs + report
+//   post   <raw.glb> <out.glb> '<job json>'     the one post step on one Meshy raw (lib/post.mjs)
+//   pass   <pack…|--all> [--write]             decimate to budget, texture cap, emissive policy on
+//                                               the SHIPPED GLBs (dry run unless --write; a compliant
+//                                               file is left byte-identical)
+//   lod    <pack>                               defight (judged) + LOD1/LOD2 + --check (tools/lod)
+//   thumbs <pack> [--only A,B]                  render each row's screenshot (512², tools/meshy)
+//   flicker <pack…|--all> [--record]           static z-fight probe; --record renders every file over
+//                                               the limit (headless) and writes flicker-baseline.json
+//   report [pack…] [--md file] [--json file]   the budget report (tris vs budget, MiB, textures, LODs)
+//   check  [pack…] [--json file] [--summary file]   the CI: exit 1 on any error not in allow.json
+import fs from 'node:fs';
+import path from 'node:path';
+import { execFileSync } from 'node:child_process';
+import { REPO } from './lib/deps.mjs';
+
+const [cmd, ...rest] = process.argv.slice(2);
+const flag = (/** @type {string} */ f) => rest.includes(f);
+const opt = (/** @type {string} */ f) => (rest.includes(f) ? rest[rest.indexOf(f) + 1] : null);
+const positional = () => rest.filter((a, i) => !a.startsWith('--') && !(i > 0 && ['--md', '--json', '--summary', '--only'].includes(rest[i - 1])));
+
+/** where each pack's recipe lives (what makes its GLBs from Meshy raws / procedural code) */
+export const RECIPES = {
+	'architecture-kit': ['tools/architecture-kit/build.mjs', '--no-thumbs'],
+	'scifi-kit': ['tools/scifi-kit/build.mjs', '--no-thumbs'],
+	'town-kit': ['tools/town-kit/build.mjs', '--no-thumbs'],
+	'interactive-kit': ['tools/interactive-kit/build.mjs'],
+	'nature-kit': ['nature-kit/build/finalize.mjs', '--no-thumbs'],
+	'props-kit': ['props-kit/_src/build.mjs', '--no-shots'],
+	'interior-kit': ['interior-kit/_src/build.mjs', '--no-shots']
+};
+
+const node = (/** @type {string[]} */ args) => execFileSync(process.execPath, args, { cwd: REPO, stdio: 'inherit' });
+
+async function main() {
+	switch (cmd) {
+		case 'check': {
+			const { runChecks } = await import('./lib/check.mjs');
+			const { printFindings, summaryMarkdown } = await import('./lib/report.mjs');
+			const packs = positional();
+			const t0 = Date.now();
+			const r = await runChecks(REPO, { packs: packs.length ? packs : null });
+			const errors = printFindings(r.findings);
+			console.log(`\n${r.items.length} items checked in ${((Date.now() - t0) / 1000).toFixed(1)} s`);
+			if (opt('--json')) fs.writeFileSync(/** @type {string} */ (opt('--json')), JSON.stringify(r, null, 1) + '\n');
+			if (opt('--summary')) fs.appendFileSync(/** @type {string} */ (opt('--summary')), summaryMarkdown(r));
+			process.exitCode = errors ? 1 : 0;
+			return;
+		}
+		case 'report': {
+			const { runChecks } = await import('./lib/check.mjs');
+			const { budgetMarkdown } = await import('./lib/report.mjs');
+			const packs = positional();
+			const r = await runChecks(REPO, { packs: packs.length ? packs : null });
+			const md = budgetMarkdown(r);
+			if (opt('--md')) fs.writeFileSync(/** @type {string} */ (opt('--md')), md);
+			else process.stdout.write(md);
+			if (opt('--json')) fs.writeFileSync(/** @type {string} */ (opt('--json')), JSON.stringify(r.items, null, 1) + '\n');
+			return;
+		}
+		case 'post': {
+			const [input, output, job] = rest;
+			if (!input || !output) throw new Error("usage: kit-build post <raw.glb> <out.glb> '<job json>'");
+			const { kitPost } = await import('./lib/post.mjs');
+			console.log(JSON.stringify(await kitPost(input, output, JSON.parse(job || '{}'))));
+			return;
+		}
+		case 'pass': {
+			const { passPack } = await import('./lib/pass.mjs');
+			const { loadConfig } = await import('./lib/check.mjs');
+			const packs = flag('--all') ? Object.keys(loadConfig(REPO).packs.packs) : positional();
+			if (!packs.length) throw new Error('usage: kit-build pass <pack…|--all> [--write]');
+			let changed = 0;
+			for (const p of packs) changed += await passPack(REPO, p, { write: flag('--write') });
+			console.log(`${changed} file(s) ${flag('--write') ? 'rewritten' : 'would change (dry run; --write to apply)'}`);
+			return;
+		}
+		case 'lod': {
+			const [pack] = positional();
+			if (!pack) throw new Error('usage: kit-build lod <pack>');
+			node(['tools/lod/defight-all.mjs', pack]);
+			node(['tools/lod/lod.mjs', pack]);
+			node(['tools/lod/lod.mjs', '--check', pack]);
+			return;
+		}
+		case 'thumbs': {
+			const [pack] = positional();
+			if (!pack) throw new Error('usage: kit-build thumbs <pack> [--only A,B]');
+			const { thumbsPack } = await import('./lib/pass.mjs');
+			const only = opt('--only')?.split(',') ?? null;
+			console.log(`${await thumbsPack(REPO, pack, only)} thumbnail(s) rendered`);
+			return;
+		}
+		case 'flicker': {
+			const { flickerPacks } = await import('./lib/flicker.mjs');
+			const { loadConfig } = await import('./lib/check.mjs');
+			const packs = flag('--all') ? Object.keys(loadConfig(REPO).packs.packs) : positional();
+			await flickerPacks(REPO, packs, { record: flag('--record') });
+			return;
+		}
+		case 'build': {
+			const [pack] = positional();
+			const recipe = RECIPES[/** @type {keyof RECIPES} */ (pack)];
+			if (!recipe) throw new Error(`kit-build build: no recipe for "${pack}" (have: ${Object.keys(RECIPES).join(', ')})`);
+			const only = opt('--only');
+			node([...recipe, ...(only ? ['--only', only] : [])]);
+			const { passPack, thumbsPack } = await import('./lib/pass.mjs');
+			await passPack(REPO, pack, { write: true });
+			node(['tools/lod/defight-all.mjs', pack]);
+			node(['tools/lod/lod.mjs', pack]);
+			if (!flag('--no-thumbs')) await thumbsPack(REPO, pack, only?.split(',') ?? null);
+			node(['tools/kit-build/kit-build.mjs', 'check', pack]);
+			return;
+		}
+		default:
+			console.log(fs.readFileSync(new URL(import.meta.url), 'utf8').split('\n').filter((l) => l.startsWith('//')).map((l) => l.slice(3)).join('\n'));
+			process.exitCode = cmd ? 2 : 0;
+	}
+}
+
+await main();
diff --git a/tools/kit-build/lib/check.mjs b/tools/kit-build/lib/check.mjs
new file mode 100644
index 0000000..930c691
--- /dev/null
+++ b/tools/kit-build/lib/check.mjs
@@ -0,0 +1,243 @@
+// check: the pack CI (roadmap 34 E2) — every rule a packs PR must pass, over every pack in index.json.
+//
+//   index     index.json rows: shape, files exist
+//   manifest  each pack's model list: row shape (incl. `lods`, `behavior`), names unique, files exist,
+//             no orphan GLBs
+//   size      every GLB ≤ 5 MiB (the share cap: bigger never reaches a peer), warn > 2 MiB
+//   tris      LOD0 triangles ≤ the item's category budget (packs.json)
+//   textures  largest texture side ≤ the pack's cap
+//   emissive  a pack whose policy is "none" has nothing that glows; an emissive map with a black
+//             factor is a wasted texture fetch (warn)
+//   scale     the bbox is in metres (category's largest extent, never a speck)
+//   pivot     the origin is where the item's pivot rule says (bottom-centre unless packs.json says)
+//   lods      items over 2 000 triangles ship LOD files; each file exists, is coarser than LOD0, keeps
+//             LOD0's mesh-node names and clips, and its ratio is the measured one (± 0.05)
+//   behavior  a behavior's clips exist in the GLB (and in every LOD file)
+//   flicker   the static z-fight probe (tools/lod/coplanar.mjs: coplanar triangle pairs, both facings
+//             when double-sided) ≤ 1 cm² — or no worse than the file's recorded baseline
+//             (flicker-baseline.json, written by `kit-build flicker --record` after a RENDER probe)
+//   thumb     the row's screenshot exists and decodes, ≥ 64 px
+//
+// A failure is an ERROR unless allow.json lists it (pack, item, check) with a reason; an allow-list
+// entry that matched nothing is reported so it gets cleaned up.
+import fs from 'node:fs';
+import path from 'node:path';
+import { load } from './deps.mjs';
+import { inspectGlb } from './inspect.mjs';
+import { indexRowProblems, itemRowProblems, behaviorClipProblems, pivotProblem, scaleProblem, safeRel } from './rules.mjs';
+import { probeFile } from '../../lod/coplanar.mjs';
+
+const sharp = (await load('sharp')).default;
+const isUrl = (/** @type {any} */ p) => typeof p === 'string' && /^https?:\/\//.test(p);
+const KB = (/** @type {number} */ b) => `${(b / 1024 / 1024).toFixed(2)} MiB`;
+
+/** @param {string} repo */
+export function loadConfig(repo) {
+	const dir = path.join(repo, 'tools/kit-build');
+	const read = (/** @type {string} */ f, /** @type {any} */ dflt) => (fs.existsSync(path.join(dir, f)) ? JSON.parse(fs.readFileSync(path.join(dir, f), 'utf8')) : dflt);
+	return { packs: read('packs.json', null), allow: read('allow.json', { allow: [] }).allow, baseline: read('flicker-baseline.json', { files: {} }).files };
+}
+
+/** the item's resolved policy @param {any} cfg @param {string} pack @param {string} item */
+export function itemPolicy(cfg, pack, item) {
+	const p = cfg.packs.packs[pack];
+	if (!p) return null;
+	const o = p.items?.[item] ?? {};
+	const category = o.category ?? p.category;
+	const cat = cfg.packs.categories[category];
+	if (!cat) throw new Error(`packs.json: ${pack}/${item} has unknown category "${category}"`);
+	return { category, budget: cat.tris, maxExtent: cat.maxExtent, pivot: o.pivot ?? p.pivot ?? 'bottom-center', textureCap: o.textureCap ?? p.textureCap, emissive: p.emissive };
+}
+
+/**
+ * @param {string} repo the packs checkout
+ * @param {{packs?: string[] | null, flicker?: boolean}} [o]
+ */
+export async function runChecks(repo, o = {}) {
+	const cfg = loadConfig(repo);
+	const L = cfg.packs.limits;
+	/** @type {{level: 'error'|'warn', pack: string, item: string, check: string, msg: string, file?: string, allowed?: string}[]} */
+	const findings = [];
+	/** @type {any[]} */
+	const items = [];
+	const add = (/** @type {'error'|'warn'} */ level, /** @type {string} */ pack, /** @type {string} */ item, /** @type {string} */ check, /** @type {string} */ msg, /** @type {string} */ file = '') =>
+		findings.push({ level, pack, item, check, msg, ...(file ? { file } : {}) });
+
+	const index = JSON.parse(fs.readFileSync(path.join(repo, 'index.json'), 'utf8'));
+	if (!Array.isArray(index)) add('error', '-', '-', 'index', 'index.json is not an array');
+	const seenPacks = new Set();
+	/** baseline entries a file over the limit leaned on */
+	const baselineUsed = new Set();
+	for (const row of index) {
+		const name = row?.name ?? '?';
+		for (const m of indexRowProblems(row)) add('error', name, '-', 'index', m);
+		if (seenPacks.has(name)) add('error', name, '-', 'index', 'duplicate pack name');
+		seenPacks.add(name);
+		for (const k of ['value', 'attribution', 'cover']) if (typeof row[k] === 'string' && !isUrl(row[k]) && !fs.existsSync(path.join(repo, row[k]))) add('error', name, '-', 'index', `${k} ${row[k]} does not exist`);
+		if (typeof row.zip === 'string' && !fs.existsSync(path.join(repo, row.zip.replace(/^\//, '')))) add('error', name, '-', 'index', `zip ${row.zip} does not exist`);
+		if (row.value && !cfg.packs.packs[name]) add('error', name, '-', 'index', 'pack has no policy in tools/kit-build/packs.json (texture cap, emissive, category, pivot)');
+	}
+
+	for (const row of index) {
+		if (!row?.value || isUrl(row.value)) continue;
+		const pack = row.name;
+		if (o.packs && !o.packs.includes(pack)) continue;
+		const listFile = path.join(repo, row.value);
+		if (!fs.existsSync(listFile)) continue;
+		/** @type {any[]} */
+		let rows;
+		try {
+			rows = JSON.parse(fs.readFileSync(listFile, 'utf8'));
+		} catch (e) {
+			add('error', pack, '-', 'manifest', `${row.value} is not JSON: ${/** @type {Error} */ (e).message}`);
+			continue;
+		}
+		if (!Array.isArray(rows)) {
+			add('error', pack, '-', 'manifest', `${row.value} is not an array`);
+			continue;
+		}
+		const base = path.dirname(listFile);
+		const referenced = new Set();
+		const names = new Set();
+		for (const r of rows) {
+			const item = r?.name ?? '?';
+			for (const m of itemRowProblems(r)) add('error', pack, item, 'manifest', m);
+			if (names.has(item)) add('error', pack, item, 'manifest', 'duplicate item name');
+			names.add(item);
+			const glbRef = r?.variants?.['glTF-Binary'];
+			if (typeof glbRef !== 'string' || isUrl(glbRef) || !safeRel(glbRef)) continue; // upstream-fetch rows (khronos) carry no bytes here
+			const dir = path.join(base, item);
+			const glb = path.join(dir, 'glTF-Binary', glbRef);
+			referenced.add(path.resolve(glb));
+			if (!fs.existsSync(glb)) {
+				add('error', pack, item, 'manifest', `glTF-Binary/${glbRef} does not exist`);
+				continue;
+			}
+			const pol = itemPolicy(cfg, pack, item);
+			const info = await inspectGlb(glb);
+			const rec = { ...info, pack, item, file: path.relative(repo, glb), category: pol?.category, budget: pol?.budget, lods: [] };
+			items.push(rec);
+			// size
+			const sizeCheck = (/** @type {string} */ f, /** @type {number} */ bytes) => {
+				if (bytes > L.glbFailBytes) add('error', pack, item, 'size', `${path.basename(f)} is ${KB(bytes)} — over the 5 MiB share cap (it never reaches a peer)`, f);
+				else if (bytes > L.glbWarnBytes) add('warn', pack, item, 'size', `${path.basename(f)} is ${KB(bytes)} (> 2 MiB)`, f);
+			};
+			sizeCheck(rec.file, info.bytes);
+			if (pol) {
+				if (info.tris > pol.budget) add('error', pack, item, 'tris', `${info.tris} triangles is over the ${pol.category} budget of ${pol.budget} — decimate (kit-build pass --write) or re-categorise`);
+				const big = Math.max(0, ...info.textures.map((t) => Math.max(...(t.size ?? [0]))));
+				if (big > pol.textureCap) add('error', pack, item, 'textures', `a ${big}² texture is over the pack's ${pol.textureCap} cap (kit-build pass --write)`);
+				if (pol.emissive === 'none') {
+					const lit = info.materials.filter((m) => m.emissive || m.emissiveTexture).map((m) => m.name || '(unnamed)');
+					if (lit.length) add('error', pack, item, 'emissive', `the pack's policy is "nothing glows" but ${lit.join(', ')} ${lit.length > 1 ? 'are' : 'is'} emissive (kit-build pass --write)`);
+				}
+				const s = scaleProblem(info.size, pol.maxExtent, L.minExtent);
+				if (s) add('error', pack, item, 'scale', s);
+				const pv = pivotProblem(info.min, info.max, pol.pivot);
+				if (pv) add('error', pack, item, 'pivot', `${pv}; rule "${pol.pivot}"`);
+			}
+			for (const m of info.materials) if (m.emissiveTexture && !m.emissive) add('warn', pack, item, 'emissive', `material ${m.name || '(unnamed)'} has an emissive map with a black factor (a wasted texture)`);
+			// lods
+			const lods = Array.isArray(r.lods) ? r.lods : [];
+			if (!lods.length && info.tris > L.lodRequiredOver) add('error', pack, item, 'lods', `${info.tris} triangles and no LOD files (node tools/kit-build/kit-build.mjs lod ${pack})`);
+			for (const l of lods) {
+				if (!safeRel(l?.file)) continue;
+				const lf = path.join(dir, 'glTF-Binary', l.file);
+				referenced.add(path.resolve(lf));
+				if (!fs.existsSync(lf)) {
+					add('error', pack, item, 'lods', `${l.file} does not exist`);
+					continue;
+				}
+				const li = await inspectGlb(lf);
+				rec.lods.push({ file: path.relative(repo, lf), bytes: li.bytes, tris: li.tris, ratio: l.ratio });
+				sizeCheck(path.relative(repo, lf), li.bytes);
+				if (li.tris >= info.tris) add('error', pack, item, 'lods', `${l.file} has ${li.tris} triangles, not fewer than LOD0's ${info.tris}`);
+				const measured = info.tris ? li.tris / info.tris : 0;
+				if (typeof l.ratio === 'number' && Math.abs(measured - l.ratio) > 0.05) add('error', pack, item, 'lods', `${l.file}: ratio ${l.ratio} but the file has ${(measured * 100).toFixed(0)} % of LOD0's triangles`);
+				const lod0Names = new Set(info.meshNodes);
+				const strangers = li.meshNodes.filter((n) => !lod0Names.has(n));
+				if (strangers.length && li.meshNodes.length !== info.meshNodes.length) add('error', pack, item, 'lods', `${l.file} has mesh nodes LOD0 does not (${strangers.slice(0, 4).join(', ')}) — core swaps levels BY NODE NAME`);
+				const missing = info.animations.filter((a) => !li.animations.includes(a));
+				if (missing.length) add('error', pack, item, 'lods', `${l.file} lacks LOD0's clips ${missing.join(', ')} (an animated item keeps animating at every level)`);
+				if (r.behavior) for (const m of behaviorClipProblems(r.behavior, li.animations)) add('error', pack, item, 'behavior', `${l.file}: ${m}`);
+				if (o.flicker !== false) await flicker(path.relative(repo, lf));
+			}
+			if (r.behavior) for (const m of behaviorClipProblems(r.behavior, info.animations)) add('error', pack, item, 'behavior', m);
+			// thumb
+			const shot = r.screenshot;
+			if (!isUrl(shot)) {
+				const cands = shot ? [shot] : ['thumb.webp', 'thumb.png'];
+				const found = cands.map((c) => path.join(dir, c)).find((f) => fs.existsSync(f));
+				if (!found) add('error', pack, item, 'thumb', `no thumbnail (${cands.join(' / ')}) — node tools/kit-build/kit-build.mjs thumbs ${pack} --only ${item}`);
+				else {
+					try {
+						const meta = await sharp(found).metadata();
+						if (Math.min(meta.width ?? 0, meta.height ?? 0) < L.thumbMinPx) add('error', pack, item, 'thumb', `${path.relative(dir, found)} is ${meta.width}×${meta.height} (< ${L.thumbMinPx} px)`);
+					} catch (e) {
+						add('error', pack, item, 'thumb', `${path.relative(dir, found)} does not decode: ${/** @type {Error} */ (e).message}`);
+					}
+				}
+			}
+			if (o.flicker !== false) await flicker(rec.file);
+
+			/** the static z-fight probe against the 1 cm² limit or the recorded baseline @param {string} f */
+			async function flicker(f) {
+				const pr = await probeFile(path.join(repo, f));
+				const cm2 = pr.area * 1e4;
+				const bl = cfg.baseline[f];
+				const ref = f === rec.file ? rec : rec.lods.find((/** @type {any} */ x) => x.file === f);
+				if (ref) Object.assign(ref, { flickerPairs: pr.pairs, flickerCm2: +cm2.toFixed(2) });
+				if (cm2 <= L.flickerCm2) return;
+				if (bl) baselineUsed.add(f);
+				if (bl && cm2 <= bl.cm2 * 1.02 + 0.05) return;
+				add(
+					'error',
+					pack,
+					item,
+					'flicker',
+					bl
+						? `${path.basename(f)}: ${pr.pairs} coplanar pairs, ${cm2.toFixed(1)} cm² — WORSE than its baseline ${bl.cm2} cm²`
+						: `${path.basename(f)}: ${pr.pairs} coplanar pairs, ${cm2.toFixed(1)} cm² of overlap (limit ${L.flickerCm2} cm²) — node tools/lod/defight-all.mjs ${pack}, then kit-build flicker ${pack} --record if the render probe passes`,
+					f
+				);
+			}
+		}
+		// orphans: GLBs under the pack folder that no row references (shipped bytes nobody loads)
+		for (const f of walk(base)) if (/\.glb$/i.test(f) && !referenced.has(path.resolve(f))) add('warn', pack, '-', 'manifest', `${path.relative(repo, f)} is not referenced by ${row.value}`, path.relative(repo, f));
+	}
+
+	// baseline entries nothing needs any more (the file is gone, or now under the limit)
+	if (o.flicker !== false)
+		for (const f of Object.keys(cfg.baseline)) {
+			const pack = f.split('/')[0];
+			if ((!o.packs || o.packs.includes(pack)) && !baselineUsed.has(f)) add('warn', pack, f.split('/')[1] ?? '-', 'flicker', `${f} is in flicker-baseline.json but is gone or now under the limit — re-record: kit-build flicker ${pack} --record`, f);
+		}
+
+	// the allow-list
+	const used = new Set();
+	for (const f of findings) {
+		if (f.level !== 'error') continue;
+		const hit = cfg.allow.findIndex((/** @type {any} */ a) => a.pack === f.pack && (a.item === f.item || a.item === '*') && a.check === f.check && (!a.file || a.file === f.file));
+		if (hit >= 0) {
+			f.allowed = cfg.allow[hit].reason;
+			used.add(hit);
+		}
+	}
+	cfg.allow.forEach((/** @type {any} */ a, /** @type {number} */ i) => {
+		if (!used.has(i) && (!o.packs || o.packs.includes(a.pack))) add('warn', a.pack, a.item, 'allow', `allow-list entry for "${a.check}" matched nothing — remove it from tools/kit-build/allow.json`);
+	});
+	return { findings, items };
+}
+
+/** @param {string} dir @returns {string[]} */
+function walk(dir) {
+	/** @type {string[]} */
+	const out = [];
+	for (const e of fs.readdirSync(dir, { withFileTypes: true })) {
+		if (e.name.startsWith('.') || e.name === 'node_modules' || e.name === '_src' || e.name === 'build') continue;
+		const p = path.join(dir, e.name);
+		if (e.isDirectory()) out.push(...walk(p));
+		else out.push(p);
+	}
+	return out;
+}
diff --git a/tools/kit-build/lib/deps.mjs b/tools/kit-build/lib/deps.mjs
new file mode 100644
index 0000000..5d31fb5
--- /dev/null
+++ b/tools/kit-build/lib/deps.mjs
@@ -0,0 +1,26 @@
+// The one dependency set every pack tool uses: tools/meshy's node_modules (`cd tools/meshy && npm ci`).
+// MESHY_TOOLS overrides the folder (a lane that keeps its tools checkout elsewhere).
+//
+// ONE MODULE INSTANCE: gltf-transform checks `instanceof` (prune, flatten, …), so a Document must be
+// read and transformed through the SAME build of it. Every pack tool (kit-build, tools/lod, the kit
+// builds) loads the CommonJS build through `load` here; meshy-post (tools/meshy/lib/post.js) uses the
+// ES build internally and is only ever handed FILE paths.
+import path from 'node:path';
+import { createRequire } from 'node:module';
+import { fileURLToPath, pathToFileURL } from 'node:url';
+
+export const HERE = path.dirname(fileURLToPath(import.meta.url));
+export const REPO = path.resolve(HERE, '../../..');
+export const TOOLS = process.env.MESHY_TOOLS || path.join(REPO, 'tools/meshy');
+const req = createRequire(path.join(TOOLS, 'package.json'));
+/** a package from tools/meshy's node_modules @param {string} id @returns {Promise<any>} */
+export const load = async (id) => import(pathToFileURL(req.resolve(id)).href);
+/** import a file of tools/meshy (lib/post.js, lib/thumb.js) @param {string} rel */
+export const tool = async (rel) => import(pathToFileURL(path.join(TOOLS, rel)).href);
+
+const { NodeIO, Logger } = await load('@gltf-transform/core');
+const { ALL_EXTENSIONS } = await load('@gltf-transform/extensions');
+/** a NodeIO with every extension, quiet (stdout carries reports) */
+export function makeIO() {
+	return new NodeIO().registerExtensions(ALL_EXTENSIONS).setLogger(new Logger(Logger.Verbosity.ERROR));
+}
diff --git a/tools/kit-build/lib/flicker.mjs b/tools/kit-build/lib/flicker.mjs
new file mode 100644
index 0000000..0e3ff32
--- /dev/null
+++ b/tools/kit-build/lib/flicker.mjs
@@ -0,0 +1,94 @@
+// flicker: the z-fight gate's two probes.
+//
+// STATIC (CI, every PR): tools/lod/coplanar.mjs — triangle pairs in one plane (facing within 1°,
+// corners within 1 mm; both facings when the material is double-sided) overlapping by > 1 mm².
+// Deterministic, no GPU, ~15 s for every pack. But it OVER-counts: a coplanar pair hidden inside a
+// piece, or one whose two layers carry the same texels, never shows. 33-pack-fix-lod therefore
+// judged every file by a RENDER: defight rewrites a file only when the render flickers clearly less.
+//
+// RENDER (local, headless Chromium — tools/lod/judge.mjs `flicker`): 12 orbit poses, each a
+// micro-triplet (±0.02°); a pixel flickers when the middle frame disagrees with both neighbours while
+// they agree — the in-app probe's metric, offline.
+//
+// `kit-build flicker <pack…> --record` renders every file over the static limit and records it in
+// flicker-baseline.json {file: {cm2, pairs, px, why}} — refused (not recorded, exit 1) when the render
+// flickers more than LIMIT_PX. The CI then lets such a file through at its recorded area, never worse.
+import fs from 'node:fs';
+import path from 'node:path';
+import { probeFile } from '../../lod/coplanar.mjs';
+import { loadConfig } from './check.mjs';
+import { packRows } from './pass.mjs';
+
+/** the render flicker a recorded file may have at most (512², 12 poses — see the header) */
+export const LIMIT_PX = 400;
+
+/**
+ * @param {string} repo @param {string[]} packs @param {{record?: boolean}} [o]
+ */
+export async function flickerPacks(repo, packs, o = {}) {
+	const cfg = loadConfig(repo);
+	const limit = cfg.packs.limits.flickerCm2;
+	const basePath = path.join(repo, 'tools/kit-build/flicker-baseline.json');
+	const doc = fs.existsSync(basePath) ? JSON.parse(fs.readFileSync(basePath, 'utf8')) : { files: {} };
+	const defight = fs.existsSync(path.join(repo, 'tools/lod/defight-report.json')) ? JSON.parse(fs.readFileSync(path.join(repo, 'tools/lod/defight-report.json'), 'utf8')) : {};
+	/** @type {any} */
+	let judge = null;
+	let refused = 0;
+	try {
+		for (const pack of packs) {
+			for (const { row, glb } of packRows(repo, pack)) {
+				const files = [glb, ...(Array.isArray(row.lods) ? row.lods.map((/** @type {any} */ l) => path.join(path.dirname(glb), l.file)) : [])];
+				for (const f of files) {
+					if (!fs.existsSync(f)) continue;
+					const rel = path.relative(repo, f);
+					const pr = await probeFile(f);
+					const cm2 = +(pr.area * 1e4).toFixed(2);
+					if (cm2 <= limit) {
+						if (o.record && doc.files[rel]) delete doc.files[rel];
+						continue;
+					}
+					if (!o.record) {
+						const bl = doc.files[rel];
+						console.log(`${bl ? (cm2 <= bl.cm2 * 1.02 + 0.05 ? 'baseline' : 'WORSE   ') : 'OVER    '} ${rel}: ${pr.pairs} pairs, ${cm2} cm²${bl ? ` (recorded ${bl.cm2} cm², ${bl.px} px)` : ''}`);
+						continue;
+					}
+					if (!judge) {
+						const { Judge } = await import('../../lod/judge.mjs');
+						judge = new Judge();
+						await judge.open();
+					}
+					const px = await judge.flicker(fs.readFileSync(f));
+					const isLod0 = f === glb;
+					const d = defight[`${pack}/${row.name}`];
+					const why = isLod0
+						? d?.left
+							? `defight left it: ${d.left}${d.flicker ? ` (render ${d.flicker[0]} → ${d.flicker[1]} px)` : ''}`
+							: d?.mode
+								? `defight (${d.mode}) settled the visible layers; the rest are hidden`
+								: 'not in defight-report.json (built before tools/lod or outside it)'
+						: `a level of ${row.name}: tools/lod simplifies LOD0 per primitive and only drops hidden duplicates (core draws it far away, with LOD0's material)`;
+					if (px > LIMIT_PX) {
+						refused++;
+						console.log(`REFUSED  ${rel}: ${pr.pairs} pairs, ${cm2} cm², render ${px} px > ${LIMIT_PX} — fix it (tools/lod/defight-all.mjs ${pack})`);
+						continue;
+					}
+					doc.files[rel] = { cm2, pairs: pr.pairs, px, why };
+					console.log(`recorded ${rel}: ${pr.pairs} pairs, ${cm2} cm², render ${px} px`);
+				}
+			}
+		}
+	} finally {
+		await judge?.close();
+	}
+	if (o.record) {
+		const files = Object.fromEntries(Object.entries(doc.files).sort(([a], [b]) => a.localeCompare(b)));
+		const out = {
+			note: `The static z-fight probe's accepted files (kit-build check: a file over ${limit} cm² of coplanar overlap passes only at or under its recorded area). Each was RENDERED (tools/lod/judge.mjs flicker: 512², 12 orbit poses) and flickers at most ${LIMIT_PX} px; px = that measurement. Written by: node tools/kit-build/kit-build.mjs flicker <pack> --record`,
+			limitPx: LIMIT_PX,
+			files
+		};
+		fs.writeFileSync(basePath, JSON.stringify(out, null, 1) + '\n');
+		console.log(`${Object.keys(files).length} file(s) in flicker-baseline.json${refused ? `, ${refused} REFUSED` : ''}`);
+	}
+	if (refused) process.exitCode = 1;
+}
diff --git a/tools/kit-build/lib/inspect.mjs b/tools/kit-build/lib/inspect.mjs
new file mode 100644
index 0000000..be1321b
--- /dev/null
+++ b/tools/kit-build/lib/inspect.mjs
@@ -0,0 +1,67 @@
+// inspect: what a shipped GLB IS, measured — the numbers the budget report and the CI checks read.
+import fs from 'node:fs';
+import { load, makeIO } from './deps.mjs';
+
+const { getBounds } = await load('@gltf-transform/functions');
+const io = makeIO();
+
+/** triangles DRAWN: per node that references a mesh (a kitbash instances one mesh several times) @param {any} doc */
+export function drawnTris(doc) {
+	let n = 0;
+	for (const node of doc.getRoot().listNodes()) {
+		const mesh = node.getMesh();
+		if (!mesh) continue;
+		for (const p of mesh.listPrimitives()) {
+			if (p.getMode() !== 4) continue;
+			const idx = p.getIndices();
+			n += (idx ? idx.getCount() : (p.getAttribute('POSITION')?.getCount() ?? 0)) / 3;
+		}
+	}
+	return Math.round(n);
+}
+
+/** @param {any} doc */
+export function sceneOf(doc) {
+	return doc.getRoot().getDefaultScene() ?? doc.getRoot().listScenes()[0];
+}
+
+/**
+ * @param {string} file
+ * @returns {Promise<{file: string, bytes: number, tris: number, min: number[], max: number[], size: number[],
+ *   nodes: number, meshNodes: string[], meshes: number, prims: number, materials: {name: string, doubleSided: boolean,
+ *   emissive: boolean, emissiveTexture: boolean}[], textures: {size: number[] | null, mime: string, bytes: number}[],
+ *   animations: string[], extras: any}>}
+ */
+export async function inspectGlb(file) {
+	const doc = await io.read(file);
+	return { file, bytes: fs.statSync(file).size, ...inspectDoc(doc) };
+}
+
+/** @param {any} doc */
+export function inspectDoc(doc) {
+	const root = doc.getRoot();
+	const scene = sceneOf(doc);
+	const b = scene ? getBounds(scene) : { min: [0, 0, 0], max: [0, 0, 0] };
+	const finite = b.min.every(Number.isFinite) && b.max.every(Number.isFinite);
+	const min = finite ? b.min.map((v) => +v.toFixed(4)) : [0, 0, 0];
+	const max = finite ? b.max.map((v) => +v.toFixed(4)) : [0, 0, 0];
+	return {
+		tris: drawnTris(doc),
+		min,
+		max,
+		size: [0, 1, 2].map((i) => +(max[i] - min[i]).toFixed(4)),
+		nodes: root.listNodes().length,
+		meshNodes: root.listNodes().filter((n) => n.getMesh()).map((n) => n.getName()),
+		meshes: root.listMeshes().length,
+		prims: root.listMeshes().reduce((s, m) => s + m.listPrimitives().length, 0),
+		materials: root.listMaterials().map((m) => ({
+			name: m.getName(),
+			doubleSided: m.getDoubleSided(),
+			emissive: m.getEmissiveFactor().some((v) => v > 0),
+			emissiveTexture: !!m.getEmissiveTexture()
+		})),
+		textures: root.listTextures().map((t) => ({ size: t.getSize(), mime: t.getMimeType(), bytes: t.getImage()?.byteLength ?? 0 })),
+		animations: root.listAnimations().map((a) => a.getName()),
+		extras: scene?.getExtras() ?? {}
+	};
+}
diff --git a/tools/kit-build/lib/pass.mjs b/tools/kit-build/lib/pass.mjs
new file mode 100644
index 0000000..c5bf80f
--- /dev/null
+++ b/tools/kit-build/lib/pass.mjs
@@ -0,0 +1,147 @@
+// pass: the pack-level steps on SHIPPED GLBs (LOD0 of every row), driven by packs.json —
+//   1. emissive policy   a pack whose policy is "none" keeps nothing that glows
+//   2. texture cap       any texture over the pack's cap is resized to it (same format)
+//   3. share cap         a GLB still over 5 MiB re-encodes its PNG textures as JPEG, largest first,
+//                        when every material using one is OPAQUE (the alpha channel is never read)
+//   4. decimate          LOD0 over its category's triangle budget is simplified to it (meshoptimizer,
+//                        node names and hierarchy kept) — then `kit-build lod <pack>` rebuilds levels
+// A file that needs none of it is never rewritten (byte-identical). And thumbnails.
+import fs from 'node:fs';
+import path from 'node:path';
+import { load, tool, makeIO } from './deps.mjs';
+import { drawnTris } from './inspect.mjs';
+import { loadConfig, itemPolicy } from './check.mjs';
+
+const { simplify, weld } = await load('@gltf-transform/functions');
+const { MeshoptSimplifier } = await load('meshoptimizer');
+const sharp = (await load('sharp')).default;
+const io = makeIO();
+const isUrl = (/** @type {any} */ p) => typeof p === 'string' && /^https?:\/\//.test(p);
+
+/** the local rows of a pack: [{row, dir, glb}] @param {string} repo @param {string} pack */
+export function packRows(repo, pack) {
+	const index = JSON.parse(fs.readFileSync(path.join(repo, 'index.json'), 'utf8'));
+	const entry = index.find((/** @type {any} */ r) => r.name === pack);
+	if (!entry?.value || isUrl(entry.value)) return [];
+	const listFile = path.join(repo, entry.value);
+	const base = path.dirname(listFile);
+	return JSON.parse(fs.readFileSync(listFile, 'utf8'))
+		.filter((/** @type {any} */ r) => typeof r?.variants?.['glTF-Binary'] === 'string' && !isUrl(r.variants['glTF-Binary']))
+		.map((/** @type {any} */ row) => ({ row, dir: path.join(base, row.name), glb: path.join(base, row.name, 'glTF-Binary', row.variants['glTF-Binary']) }));
+}
+
+/** the materials that use a texture @param {any} tex */
+const usersOf = (tex) => tex.listParents().filter((/** @type {any} */ p) => p.propertyType === 'Material');
+
+/** emissive policy "none": drop every emissive map and factor @param {any} doc */
+export function dropAllEmissive(doc) {
+	let n = 0;
+	for (const mat of doc.getRoot().listMaterials()) {
+		if (!mat.getEmissiveTexture() && !mat.getEmissiveFactor().some((/** @type {number} */ v) => v > 0)) continue;
+		mat.setEmissiveTexture(null).setEmissiveFactor([0, 0, 0]);
+		n++;
+	}
+	return n;
+}
+
+/** resize every texture over `cap` (largest side) to fit it, keeping its format @param {any} doc @param {number} cap */
+export async function capTextures(doc, cap) {
+	let n = 0;
+	for (const tex of doc.getRoot().listTextures()) {
+		const size = tex.getSize();
+		if (!size || Math.max(...size) <= cap) continue;
+		const img = sharp(Buffer.from(tex.getImage())).resize(cap, cap, { fit: 'inside' });
+		const png = tex.getMimeType() === 'image/png';
+		tex.setImage(new Uint8Array(await (png ? img.png({ compressionLevel: 9 }) : img.jpeg({ quality: 86 })).toBuffer())).setMimeType(png ? 'image/png' : 'image/jpeg');
+		n++;
+	}
+	return n;
+}
+
+/** PNG → JPEG (q 86, the pipeline's quality), largest first, while the GLB is over `maxBytes`, for
+ * textures only OPAQUE materials use @param {any} doc @param {number} maxBytes */
+export async function fitShareCap(doc, maxBytes) {
+	let n = 0;
+	const pngs = doc
+		.getRoot()
+		.listTextures()
+		.filter((/** @type {any} */ t) => t.getMimeType() === 'image/png' && usersOf(t).every((/** @type {any} */ m) => m.getAlphaMode() === 'OPAQUE'))
+		.sort((/** @type {any} */ a, /** @type {any} */ b) => b.getImage().byteLength - a.getImage().byteLength);
+	for (const tex of pngs) {
+		if ((await io.writeBinary(doc)).byteLength <= maxBytes) break;
+		tex.setImage(new Uint8Array(await sharp(Buffer.from(tex.getImage())).flatten().jpeg({ quality: 86 }).toBuffer())).setMimeType('image/jpeg');
+		if (tex.getURI()) tex.setURI(tex.getURI().replace(/\.png$/i, '.jpg'));
+		n++;
+	}
+	return n;
+}
+
+/** simplify to `budget` drawn triangles (meshy-post's error ladder; nodes, names, clips kept)
+ * @param {any} doc @param {number} budget */
+export async function decimateTo(doc, budget) {
+	const before = drawnTris(doc);
+	if (before <= budget) return 0;
+	await MeshoptSimplifier.ready;
+	await doc.transform(weld());
+	for (const error of [0.001, 0.005, 0.01, 0.02, 0.05]) {
+		const ratio = budget / drawnTris(doc);
+		if (ratio >= 1) break;
+		await doc.transform(simplify({ simplifier: MeshoptSimplifier, ratio, error, lockBorder: false }));
+		if (drawnTris(doc) <= budget) break;
+	}
+	return before - drawnTris(doc);
+}
+
+/**
+ * @param {string} repo @param {string} pack @param {{write?: boolean}} [o]
+ * @returns {Promise<number>} files that changed (or would)
+ */
+export async function passPack(repo, pack, o = {}) {
+	const cfg = loadConfig(repo);
+	let changed = 0;
+	let decimated = 0;
+	for (const { row, glb } of packRows(repo, pack)) {
+		if (!fs.existsSync(glb)) continue;
+		const pol = itemPolicy(cfg, pack, row.name);
+		if (!pol) continue;
+		const doc = await io.read(glb);
+		const did = [];
+		if (pol.emissive === 'none') {
+			const n = dropAllEmissive(doc);
+			if (n) did.push(`emissive dropped on ${n} material(s)`);
+		}
+		const capped = await capTextures(doc, pol.textureCap);
+		if (capped) did.push(`${capped} texture(s) resized to ${pol.textureCap}`);
+		const tris = await decimateTo(doc, pol.budget);
+		if (tris) {
+			did.push(`decimated by ${tris} triangles to the ${pol.category} budget ${pol.budget}`);
+			decimated++;
+		}
+		const fitted = await fitShareCap(doc, cfg.packs.limits.glbFailBytes);
+		if (fitted) did.push(`${fitted} opaque PNG texture(s) → JPEG to fit the 5 MiB share cap`);
+		if (!did.length) continue;
+		changed++;
+		const rel = path.relative(repo, glb);
+		if (o.write) {
+			const before = fs.statSync(glb).size;
+			await io.write(glb, doc);
+			console.log(`${rel}: ${did.join('; ')} (${before} → ${fs.statSync(glb).size} bytes)`);
+		} else console.log(`${rel}: would — ${did.join('; ')}`);
+	}
+	if (decimated) console.log(`${pack}: ${decimated} LOD0(s) decimated — run: node tools/kit-build/kit-build.mjs lod ${pack}`);
+	return changed;
+}
+
+/**
+ * Render each row's screenshot (512², transparent, yaw 35° — tools/meshy's thumbnailer, the one
+ * every kit used) to the path the row names (thumb.webp when it names none).
+ * @param {string} repo @param {string} pack @param {string[] | null} only
+ */
+export async function thumbsPack(repo, pack, only) {
+	const { renderThumbs } = await tool('lib/thumb.js');
+	const todo = packRows(repo, pack)
+		.filter(({ row, glb }) => (!only || only.includes(row.name)) && fs.existsSync(glb) && !isUrl(row.screenshot))
+		.map(({ row, dir, glb }) => ({ glb, out: path.join(dir, row.screenshot ?? 'thumb.webp') }));
+	if (todo.length) await renderThumbs(todo, { size: 512, bg: null, yaw: 35 });
+	return todo.length;
+}
diff --git a/tools/kit-build/lib/post.mjs b/tools/kit-build/lib/post.mjs
new file mode 100644
index 0000000..ad4abe9
--- /dev/null
+++ b/tools/kit-build/lib/post.mjs
@@ -0,0 +1,535 @@
+// post: THE pack post step (roadmap 34 E2). Every kit used to carry its own fork of it —
+// tools/architecture-kit, tools/scifi-kit and tools/town-kit had kit-post.mjs, nature-kit/build/finalize.mjs,
+// props-kit/_src/build.mjs and interior-kit/_src/build.mjs their own grade / emissive / flat-for-sync
+// helpers. They now all import from here; each function below is the fork's code unchanged (same
+// sharp calls, same JPEG quality, same order), so a rebuild writes the same bytes.
+//
+//   raw Meshy GLB → pre-rotate (Meshy often lays a floor tile or roof slab upright, and meshy-post
+//   only turns about Y) → meshy-post (weld, decimate to targetTris, stretch to the exact dims, pivot,
+//   textures to the cap as JPEG) → SEAM CLAMP → offset → EMISSIVE POLICY + albedo grade → recolor →
+//   glow mask → prune → defight → pack GLB.
+//
+// kitPost(input, output, job): job = meshy-post's job + {
+//   preRotate?: {x?, y?, z?} degrees, clamp?: "x" | "xz" | "xyz" | "x-y" …, eps?: metres (default 0.04),
+//   offset?: [x, y, z] metres applied last, albedo?: {saturation, brightness, hue} grade of the base colour,
+//   dropEmissive?: false to keep it (THE EMISSIVE POLICY: by default nothing a post step builds glows unless
+//   the job says so — `glow` below, or dropEmissive: false),
+//   glow?: {hue: [lo, hi], sat, val, strength} — light the albedo's own light strips (glowMask),
+//   recolor?: {hue: [lo, hi], sat, val, shift, minSat} — grade that hue band only (recolor),
+//   defight?: false to skip the z-fight pass (town-kit runs it itself, with a judge) }
+// `clamp` lists axes; a trailing "-y" etc. means "the MIN face of y only" (a floor's bottom).
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import { load, tool, makeIO, TOOLS } from './deps.mjs';
+import { defightFile } from '../../lod/defight.mjs';
+
+export { TOOLS };
+const { KHRMaterialsEmissiveStrength } = await load('@gltf-transform/extensions');
+const { getBounds, transformMesh, prune, flatten, clearNodeTransform, compactPrimitive } = await load('@gltf-transform/functions');
+const { postProcess } = await tool('lib/post.js');
+const sharp = (await load('sharp')).default;
+
+const io = makeIO();
+const AX = { x: 0, y: 1, z: 2 };
+
+/** column-major 4x4 rotation about one axis @param {'x'|'y'|'z'} axis @param {number} deg */
+export function rot(axis, deg) {
+	const a = (deg * Math.PI) / 180;
+	const c = Math.cos(a);
+	const s = Math.sin(a);
+	if (axis === 'x') return [1, 0, 0, 0, 0, c, s, 0, 0, -s, c, 0, 0, 0, 0, 1];
+	if (axis === 'y') return [c, 0, -s, 0, 0, 1, 0, 0, s, 0, c, 0, 0, 0, 0, 1];
+	return [c, s, 0, 0, -s, c, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1];
+}
+
+/** Parse "xz" / "x-y" / "+y" into [{axis, side}] (side: -1 min, +1 max, 0 both). @param {string} spec */
+export function parseClamp(spec) {
+	const out = [];
+	let sign = 0;
+	for (const ch of spec || '') {
+		if (ch === '-') sign = -1;
+		else if (ch === '+') sign = 1;
+		else if (ch in AX) {
+			out.push({ axis: AX[/** @type {'x'|'y'|'z'} */ (ch)], side: sign });
+			sign = 0;
+		}
+	}
+	return out;
+}
+
+/**
+ * The seam clamp is what makes pieces snap without gaps: Meshy's ends are never quite planar (a
+ * stone sticks out 2 cm, the next one is 3 cm short), so after the stretch every vertex within
+ * `eps` of a bbox face named in `clamp` is moved ONTO that face. Two walls placed end to end then
+ * share one exact plane at their joint. Returns how many vertices moved.
+ * @param {any} doc @param {string} spec @param {number} eps
+ */
+export function seamClamp(doc, spec, eps = 0.04) {
+	const faces = parseClamp(spec);
+	if (!faces.length) return 0;
+	const scene = doc.getRoot().getDefaultScene() ?? doc.getRoot().listScenes()[0];
+	const b = getBounds(scene);
+	let moved = 0;
+	const seen = new Set();
+	for (const mesh of doc.getRoot().listMeshes()) {
+		for (const prim of mesh.listPrimitives()) {
+			const pos = prim.getAttribute('POSITION');
+			if (!pos || seen.has(pos)) continue;
+			seen.add(pos);
+			const v = [0, 0, 0];
+			for (let i = 0; i < pos.getCount(); i++) {
+				pos.getElement(i, v);
+				let changed = false;
+				for (const { axis, side } of faces) {
+					if (side <= 0 && v[axis] - b.min[axis] < eps && v[axis] !== b.min[axis]) {
+						v[axis] = b.min[axis];
+						changed = true;
+					}
+					if (side >= 0 && b.max[axis] - v[axis] < eps && v[axis] !== b.max[axis]) {
+						v[axis] = b.max[axis];
+						changed = true;
+					}
+				}
+				if (changed) {
+					pos.setElement(i, v);
+					moved++;
+				}
+			}
+		}
+	}
+	return moved;
+}
+
+/** rgb (0-1) → [h°, s, v] */
+export function hsv(/** @type {number} */ r, /** @type {number} */ g, /** @type {number} */ b) {
+	const max = Math.max(r, g, b);
+	const d = max - Math.min(r, g, b);
+	const h = d === 0 ? 0 : max === r ? (60 * ((g - b) / d) + 360) % 360 : max === g ? 60 * ((b - r) / d) + 120 : 60 * ((r - g) / d) + 240;
+	return [h, max ? d / max : 0, max];
+}
+
+/**
+ * Sci-fi pieces carry their own lights (a door's light stripes, a pad's rings, a screen): Meshy
+ * paints them into the albedo as bright teal but ships no usable emissive map. The mask keeps every
+ * albedo pixel whose hue is in [lo, hi]° with saturation ≥ sat and value ≥ val (0-1), black
+ * elsewhere, and becomes the emissive texture — so exactly the painted lights glow, never the teal
+ * PAINT (darker) or the white panels (unsaturated). Returns the fraction of pixels lit (in %), 0
+ * when the material has no albedo.
+ * @param {any} doc @param {any} mat @param {{hue: number[], sat?: number, val?: number, strength?: number}} o
+ */
+export async function glowMask(doc, mat, o) {
+	const tex = mat.getBaseColorTexture();
+	if (!tex) return 0;
+	const { data, info } = await sharp(Buffer.from(tex.getImage())).removeAlpha().raw().toBuffer({ resolveWithObject: true });
+	const out = Buffer.alloc(data.length);
+	let lit = 0;
+	for (let i = 0; i < data.length; i += 3) {
+		const r = data[i] / 255;
+		const g = data[i + 1] / 255;
+		const b = data[i + 2] / 255;
+		const max = Math.max(r, g, b);
+		const d = max - Math.min(r, g, b);
+		const h = d === 0 ? 0 : max === r ? (60 * ((g - b) / d) + 360) % 360 : max === g ? 60 * ((b - r) / d) + 120 : 60 * ((r - g) / d) + 240;
+		if (max >= (o.val ?? 0.55) && d / (max || 1) >= (o.sat ?? 0.35) && h >= o.hue[0] && h <= o.hue[1]) {
+			out[i] = data[i];
+			out[i + 1] = data[i + 1];
+			out[i + 2] = data[i + 2];
+			lit++;
+		}
+	}
+	const img = await sharp(out, { raw: { width: info.width, height: info.height, channels: 3 } }).jpeg({ quality: 88 }).toBuffer();
+	const em = doc.createTexture(`${mat.getName() || 'mat'}_glow`).setImage(new Uint8Array(img)).setMimeType('image/jpeg');
+	mat.setEmissiveTexture(em).setEmissiveFactor([1, 1, 1]);
+	if (o.strength && o.strength !== 1) {
+		const ext = doc.createExtension(KHRMaterialsEmissiveStrength);
+		mat.setExtension('KHR_materials_emissive_strength', ext.createEmissiveStrength().setEmissiveStrength(o.strength));
+	}
+	return +((100 * lit) / (info.width * info.height)).toFixed(2);
+}
+
+/**
+ * A hue-selective grade of the albedo: pixels whose hue is in [lo, hi]° (a band with lo > hi wraps
+ * through 0°, reds: [340, 15]; saturation ≥ minSat, default 0.12, so greys are left alone) get their
+ * saturation × sat, value × val and hue + shift° — e.g. the wall's all-teal frame → warm gunmetal,
+ * keeping its painted shading. Returns % of pixels.
+ * @param {any} mat @param {{hue: number[], sat?: number, val?: number, shift?: number, minSat?: number}} o
+ */
+export async function recolor(mat, o) {
+	const tex = mat.getBaseColorTexture();
+	if (!tex) return 0;
+	const { data, info } = await sharp(Buffer.from(tex.getImage())).removeAlpha().raw().toBuffer({ resolveWithObject: true });
+	let n = 0;
+	for (let i = 0; i < data.length; i += 3) {
+		const [h, s, v] = hsv(data[i] / 255, data[i + 1] / 255, data[i + 2] / 255);
+		const inBand = o.hue[0] <= o.hue[1] ? h >= o.hue[0] && h <= o.hue[1] : h >= o.hue[0] || h <= o.hue[1];
+		if (s < (o.minSat ?? 0.12) || !inBand) continue;
+		const s2 = Math.min(1, s * (o.sat ?? 1));
+		const v2 = Math.min(1, v * (o.val ?? 1));
+		// back to rgb: keep the pixel's own channel ratios' hue, re-spread for s2/v2
+		const h2 = (h + (o.shift ?? 0) + 360) % 360;
+		const c = v2 * s2;
+		const x = c * (1 - Math.abs(((h2 / 60) % 2) - 1));
+		const m = v2 - c;
+		const [r, g, b] = h2 < 60 ? [c, x, 0] : h2 < 120 ? [x, c, 0] : h2 < 180 ? [0, c, x] : h2 < 240 ? [0, x, c] : h2 < 300 ? [x, 0, c] : [c, 0, x];
+		data[i] = Math.round((r + m) * 255);
+		data[i + 1] = Math.round((g + m) * 255);
+		data[i + 2] = Math.round((b + m) * 255);
+		n++;
+	}
+	tex.setImage(new Uint8Array(await sharp(data, { raw: { width: info.width, height: info.height, channels: 3 } }).jpeg({ quality: 88 }).toBuffer())).setMimeType('image/jpeg');
+	return +((100 * n) / (info.width * info.height)).toFixed(2);
+}
+
+/**
+ * The kit post step (architecture / sci-fi / town): see the header.
+ * @param {string} input @param {string} output @param {any} job
+ */
+export async function kitPost(input, output, job) {
+	let src = input;
+	const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'kit-post-'));
+	try {
+		if (job.preRotate && Object.values(job.preRotate).some(Boolean)) {
+			const doc = await io.read(input);
+			for (const axis of /** @type {const} */ (['x', 'y', 'z'])) {
+				const deg = job.preRotate[axis];
+				if (!deg) continue;
+				// bake node transforms first would be meshy-post's job; Meshy raws are a
+				// single identity node, so rotating the mesh data is exact here
+				for (const mesh of doc.getRoot().listMeshes()) transformMesh(mesh, /** @type {any} */ (rot(axis, deg)));
+			}
+			src = path.join(tmp, 'rotated.glb');
+			await io.write(src, doc);
+		}
+		const mid = path.join(tmp, 'post.glb');
+		const report = await postProcess(src, mid, job);
+		const doc = await io.read(mid);
+		const moved = seamClamp(doc, job.clamp ?? '', job.eps ?? 0.04);
+		if (job.offset) {
+			// a piece that shares ANOTHER piece's pivot (a window sits 0.95 m up on the wall's
+			// bottom-centre origin, so both place at the same grid point and rotation)
+			const t = [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, job.offset[0] ?? 0, job.offset[1] ?? 0, job.offset[2] ?? 0, 1];
+			for (const mesh of doc.getRoot().listMeshes()) transformMesh(mesh, /** @type {any} */ (t));
+		}
+		let graded = 0;
+		for (const mat of doc.getRoot().listMaterials()) {
+			// a wall or a crate never glows: Meshy's refine sometimes ships a faint emissive map
+			// (a glowing floor is baked light in disguise) — drop it outright
+			if (job.dropEmissive !== false) mat.setEmissiveTexture(null).setEmissiveFactor([0, 0, 0]);
+			// a colour GRADE of the albedo, so every piece sits in one palette (Meshy read
+			// "oxblood" as cherry red and "slate" as lavender): sharp.modulate + JPEG
+			const tex = job.albedo && mat.getBaseColorTexture();
+			if (tex) {
+				const { saturation = 1, brightness = 1, hue = 0 } = job.albedo;
+				tex.setImage(new Uint8Array(await sharp(Buffer.from(tex.getImage())).modulate({ saturation, brightness, hue }).jpeg({ quality: 86 }).toBuffer()));
+				tex.setMimeType('image/jpeg');
+				graded++;
+			}
+		}
+		let recolored = 0;
+		if (job.recolor) for (const mat of doc.getRoot().listMaterials()) recolored += await recolor(mat, job.recolor);
+		let glowing = 0;
+		if (job.glow) for (const mat of doc.getRoot().listMaterials()) glowing += await glowMask(doc, mat, job.glow);
+		await doc.transform(prune());
+		await io.write(output, doc);
+		if (job.defight === false) return { ...report, output, clamped: moved, graded, recolored, glowing, bytesOut: fs.statSync(output).size };
+		// the seam clamp folds relief within eps of a face INTO it: coplanar layers that
+		// z-fight while the camera moves (roadmap 33 K1, the Block). Settle them last.
+		const fight = await defightFile(output, output);
+		return { ...report, output, clamped: moved, defight: { pairs: fight.before, dropped: fight.dropped, pushed: fight.pushed }, graded, recolored, glowing, bytesOut: fs.statSync(output).size };
+	} finally {
+		fs.rmSync(tmp, { recursive: true, force: true });
+	}
+}
+
+// ---- the EMISSIVE POLICY on a whole file (nature-kit: nothing in nature emits light) ----
+
+/** Meshy-6 refines sometimes paint a NON-black emissive map (the oak's canopy: mean 33-47 of 255),
+ * which makes foliage glow at night and wash out by day (meshy-post only drops a fully black one).
+ * Drops every material's emissive map and factor; returns how many had one.
+ * @param {string} file */
+export async function dropEmissive(file) {
+	const doc = await io.read(file);
+	let n = 0;
+	for (const mat of doc.getRoot().listMaterials()) {
+		if (mat.getEmissiveTexture() || mat.getEmissiveFactor().some((/** @type {number} */ v) => v > 0)) n++;
+		mat.setEmissiveTexture(null).setEmissiveFactor([0, 0, 0]);
+	}
+	await doc.transform(prune());
+	await io.write(file, doc);
+	return n;
+}
+
+/** props-kit: the albedo doubles as the emissive map, so bright panes (a lantern's amber glass) light
+ * up while dark metal stays dark — a lit look with no extra texture. @param {any} doc @param {number} k */
+export function albedoGlow(doc, k) {
+	for (const mat of doc.getRoot().listMaterials()) mat.setEmissiveTexture(mat.getBaseColorTexture()).setEmissiveFactor([k, k * 0.8, k * 0.55]);
+}
+
+// ---- colour grades (0-credit palette fixes and variants) ----
+
+const rgb2hsv = (/** @type {number} */ r, /** @type {number} */ g, /** @type {number} */ b) => {
+	const mx = Math.max(r, g, b), mn = Math.min(r, g, b), d = mx - mn;
+	let h = 0;
+	if (d) h = mx === r ? ((g - b) / d) % 6 : mx === g ? (b - r) / d + 2 : (r - g) / d + 4;
+	return [(h * 60 + 360) % 360, mx ? d / mx : 0, mx];
+};
+const hsv2rgb = (/** @type {number} */ h, /** @type {number} */ s, /** @type {number} */ v) => {
+	const c = v * s, x = c * (1 - Math.abs(((h / 60) % 2) - 1)), m = v - c;
+	const [r, g, b] = h < 60 ? [c, x, 0] : h < 120 ? [x, c, 0] : h < 180 ? [0, c, x] : h < 240 ? [0, x, c] : h < 300 ? [x, 0, c] : [c, 0, x];
+	return [r + m, g + m, b + m];
+};
+const inRange = (/** @type {number} */ h, /** @type {number[]} */ [a, b]) => (a <= b ? h >= a && h <= b : h >= a || h <= b);
+
+/** nature-kit: colour grade the base-colour textures of a FILE: each rule moves pixels whose hue is
+ * in `hue` (degrees, wraps) by `shift` degrees / scales saturation `sat` and value `val`, feathered at
+ * the range edges so there is no hard seam (optional tint). The 0-credit alternative to a retexture.
+ * @param {string} file @param {any[]} rules */
+export async function gradeHue(file, rules) {
+	const doc = await io.read(file);
+	for (const mat of doc.getRoot().listMaterials()) {
+		const tex = mat.getBaseColorTexture();
+		if (!tex) continue;
+		const { data, info } = await sharp(Buffer.from(tex.getImage())).removeAlpha().raw().toBuffer({ resolveWithObject: true });
+		for (let i = 0; i < data.length; i += 3) {
+			let [h, s, v] = rgb2hsv(data[i] / 255, data[i + 1] / 255, data[i + 2] / 255);
+			/** @type {any} */
+			let tint = null;
+			for (const r of rules) {
+				if (s < (r.minSat ?? 0.12) || !inRange(h, r.hue)) continue;
+				if (r.maxSat != null && s > r.maxSat) continue;
+				if ((r.minVal != null && v < r.minVal) || (r.maxVal != null && v > r.maxVal)) continue;
+				const [a, b] = r.hue;
+				const span = (b - a + 360) % 360 || 360;
+				const t = ((h - a + 360) % 360) / span; // 0..1 across the range
+				const w = r.feather === false ? 1 : Math.min(1, Math.min(t, 1 - t) / 0.15); // feather the outer 15%
+				h = (h + (r.shift ?? 0) * w + 360) % 360;
+				s = Math.min(1, s * (1 + ((r.sat ?? 1) - 1) * w));
+				v = Math.min(1, v * (1 + ((r.val ?? 1) - 1) * w));
+				if (r.tint) tint = [r.tint, (r.amount ?? 0.3) * w, v];
+				break;
+			}
+			let [R, G, B] = hsv2rgb(h, s, v);
+			if (tint) {
+				// multiply-style tint: keep the painted value, pull the colour toward the tint
+				const [hex, k, vv] = tint;
+				const c = [1, 3, 5].map((j) => parseInt(hex.slice(j, j + 2), 16) / 255);
+				const cmax = Math.max(...c);
+				[R, G, B] = [R, G, B].map((x, j) => x * (1 - k) + (c[j] / cmax) * vv * k);
+			}
+			data[i] = R * 255; data[i + 1] = G * 255; data[i + 2] = B * 255;
+		}
+		const jpg = await sharp(data, { raw: info }).jpeg({ quality: 86 }).toBuffer();
+		tex.setImage(new Uint8Array(jpg)).setMimeType('image/jpeg');
+	}
+	await io.write(file, doc);
+}
+
+/** props-kit / interior-kit: per-channel multiply (+ offset) of every base-colour texture, so a piece
+ * Meshy painted off-palette (a pale pine table) matches the kit's oak without a paid retexture.
+ * `only: 'teal'` (interior-kit) grades only teal-ish texels (green and blue well above red, a soft
+ * mask) — a painted cupboard darkens to the pack's deep teal while its marble top and brass stay.
+ * @param {any} doc @param {{mul: number[], add?: number[], only?: string}} o */
+export async function gradeLinear(doc, { mul, add = [0, 0, 0], only }) {
+	for (const mat of doc.getRoot().listMaterials()) {
+		const tex = mat.getBaseColorTexture();
+		const img = tex?.getImage();
+		if (!img) continue;
+		if (only === 'teal') {
+			const { data, info } = await sharp(Buffer.from(img)).removeAlpha().raw().toBuffer({ resolveWithObject: true });
+			for (let i = 0; i < data.length; i += 3) {
+				const [r, g, b] = [data[i], data[i + 1], data[i + 2]];
+				const k = Math.min(1, Math.max(0, (Math.min(g, b) - r - 12) / 30)); // soft mask
+				if (k <= 0) continue;
+				for (let c = 0; c < 3; c++) data[i + c] = Math.round(data[i + c] * (1 - k + k * mul[c]));
+			}
+			tex.setImage(await sharp(data, { raw: info }).jpeg({ quality: 86 }).toBuffer()).setMimeType('image/jpeg');
+			continue;
+		}
+		tex.setImage(await sharp(Buffer.from(img)).linear(mul, add).jpeg({ quality: 86 }).toBuffer()).setMimeType('image/jpeg');
+	}
+}
+
+// ---- repairs ----
+
+/** nature-kit: bake node transforms, then drop every triangle lying entirely below `frac` of the
+ * height (Meshy likes to stand plants on a flat round "base" disc — on real terrain that reads as a
+ * coaster). Writes a cut copy into `tmpDir` and returns its path.
+ * @param {string} input @param {number} frac @param {string} tmpDir */
+export async function cutBase(input, frac, tmpDir) {
+	const doc = await io.read(input);
+	await doc.transform(flatten());
+	for (const node of doc.getRoot().listNodes()) if (node.getMesh()) clearNodeTransform(node);
+	const scene = doc.getRoot().getDefaultScene() ?? doc.getRoot().listScenes()[0];
+	const b = getBounds(scene);
+	const cut = b.min[1] + frac * (b.max[1] - b.min[1]);
+	let dropped = 0;
+	for (const mesh of doc.getRoot().listMeshes()) {
+		for (const prim of mesh.listPrimitives()) {
+			const pos = prim.getAttribute('POSITION');
+			const idx = prim.getIndices();
+			const n = idx ? idx.getCount() : pos.getCount();
+			const get = (/** @type {number} */ i) => (idx ? idx.getScalar(i) : i);
+			const keep = [];
+			for (let t = 0; t < n; t += 3) {
+				const a = get(t), c = get(t + 1), d = get(t + 2);
+				const ymax = Math.max(pos.getElement(a, [])[1], pos.getElement(c, [])[1], pos.getElement(d, [])[1]);
+				if (ymax < cut) dropped++;
+				else keep.push(a, c, d);
+			}
+			const arr = pos.getCount() > 65535 ? new Uint32Array(keep) : new Uint16Array(keep);
+			const acc = doc.createAccessor().setType('SCALAR').setArray(arr).setBuffer(pos.getBuffer());
+			prim.setIndices(acc);
+			compactPrimitive(prim);
+		}
+	}
+	await doc.transform(prune());
+	const out = path.join(tmpDir, `cut-${path.basename(path.dirname(path.dirname(input)))}-${Math.random().toString(36).slice(2, 7)}.glb`);
+	await io.write(out, doc);
+	return { out, dropped };
+}
+
+/** interior-kit: repair texels Meshy left unpainted (pure black holes in the atlas — the bed's
+ * headboard showed one): diffuse the surrounding colour into every near-black texel. 0 credits.
+ * @param {any} doc @param {{max?: number}} [o] */
+export async function inpaintBlack(doc, { max = 30 } = {}) {
+	let fixed = 0;
+	for (const mat of doc.getRoot().listMaterials()) {
+		const tex = mat.getBaseColorTexture();
+		const img = tex?.getImage();
+		if (!img) continue;
+		const { data, info } = await sharp(Buffer.from(img)).removeAlpha().raw().toBuffer({ resolveWithObject: true });
+		const { width: w, height: h } = info;
+		const hole = new Uint8Array(w * h);
+		let n = 0;
+		for (let i = 0; i < w * h; i++) if (Math.max(data[i * 3], data[i * 3 + 1], data[i * 3 + 2]) < max) (hole[i] = 1), n++;
+		if (!n) continue;
+		// onion-peel: fill hole texels that touch known texels with their neighbours' mean, repeat
+		for (let pass = 0; pass < 2048 && n; pass++) {
+			/** @type {[number, number[]][]} */
+			const next = [];
+			for (let y = 0; y < h; y++)
+				for (let x = 0; x < w; x++) {
+					const i = y * w + x;
+					if (!hole[i]) continue;
+					const acc = [0, 0, 0];
+					let k = 0;
+					for (const [dx, dy] of [[1, 0], [-1, 0], [0, 1], [0, -1], [1, 1], [-1, -1], [1, -1], [-1, 1]]) {
+						const xx = x + dx;
+						const yy = y + dy;
+						if (xx < 0 || yy < 0 || xx >= w || yy >= h) continue;
+						const j = yy * w + xx;
+						if (hole[j]) continue;
+						for (let c = 0; c < 3; c++) acc[c] += data[j * 3 + c];
+						k++;
+					}
+					if (k >= 2) next.push([i, acc.map((v) => Math.round(v / k))]);
+				}
+			if (!next.length) break;
+			for (const [i, col] of next) {
+				for (let c = 0; c < 3; c++) data[i * 3 + c] = col[c];
+				hole[i] = 0;
+				n--;
+				fixed++;
+			}
+		}
+		tex.setImage(await sharp(data, { raw: { width: w, height: h, channels: 3 } }).jpeg({ quality: 86 }).toBuffer()).setMimeType('image/jpeg');
+	}
+	return fixed;
+}
+
+/** interior-kit: repair Meshy's broken vertex normals (the bed's headboard rendered a black triangle):
+ * (1) a ZERO / NaN normal shades black — it takes the area-weighted mean of its triangles' face
+ * normals; (2) a triangle whose vertex normals point AGAINST its winding renders dark under the
+ * double-sided material — it gets its own vertices carrying its face normal. Returns { zero, flipped }.
+ * @param {any} doc */
+export function repairNormals(doc) {
+	let fixed = 0;
+	let zero = 0;
+	for (const mesh of doc.getRoot().listMeshes())
+		for (const prim of mesh.listPrimitives()) {
+			const names = prim.listSemantics();
+			const attrs = names.map((/** @type {string} */ s) => prim.getAttribute(s));
+			const P = prim.getAttribute('POSITION');
+			const N = prim.getAttribute('NORMAL');
+			const I = prim.getIndices();
+			if (!N || !I) continue;
+			{
+				const acc = new Float64Array(N.getCount() * 3);
+				const ix = I.getArray();
+				for (let t = 0; t < ix.length; t += 3) {
+					const [a, b, c] = [ix[t], ix[t + 1], ix[t + 2]].map((i) => P.getElement(i, []));
+					const u = [b[0] - a[0], b[1] - a[1], b[2] - a[2]];
+					const w = [c[0] - a[0], c[1] - a[1], c[2] - a[2]];
+					const n = [u[1] * w[2] - u[2] * w[1], u[2] * w[0] - u[0] * w[2], u[0] * w[1] - u[1] * w[0]];
+					for (let k = 0; k < 3; k++) for (let j = 0; j < 3; j++) acc[ix[t + k] * 3 + j] += n[j];
+				}
+				for (let i = 0; i < N.getCount(); i++) {
+					const n = N.getElement(i, []);
+					if (Math.hypot(...n) > 0.5) continue;
+					const m = [acc[i * 3], acc[i * 3 + 1], acc[i * 3 + 2]];
+					const l = Math.hypot(...m) || 1;
+					N.setElement(i, l > 1e-12 ? m.map((x) => x / l) : [0, 1, 0]);
+					zero++;
+				}
+			}
+			const arrays = attrs.map((/** @type {any} */ a) => Array.from(a.getArray()));
+			const idx = Array.from(I.getArray());
+			for (let t = 0; t < idx.length; t += 3) {
+				const [a, b, c] = [idx[t], idx[t + 1], idx[t + 2]].map((i) => P.getElement(i, []));
+				const u = [b[0] - a[0], b[1] - a[1], b[2] - a[2]];
+				const w = [c[0] - a[0], c[1] - a[1], c[2] - a[2]];
+				const n = [u[1] * w[2] - u[2] * w[1], u[2] * w[0] - u[0] * w[2], u[0] * w[1] - u[1] * w[0]];
+				const len = Math.hypot(...n);
+				if (len < 1e-12) continue;
+				let neg = 0;
+				for (let k = 0; k < 3; k++) {
+					const vn = N.getElement(idx[t + k], []);
+					if (vn[0] * n[0] + vn[1] * n[1] + vn[2] * n[2] < 0) neg++;
+				}
+				if (neg < 2) continue;
+				for (let k = 0; k < 3; k++) {
+					const src = idx[t + k];
+					attrs.forEach((/** @type {any} */ attr, /** @type {number} */ j) => {
+						const size = attr.getElementSize();
+						const el = names[j] === 'NORMAL' ? n.map((x) => x / len) : attr.getElement(src, []);
+						arrays[j].push(...el.slice(0, size));
+					});
+					idx[t + k] = arrays[names.indexOf('POSITION')].length / 3 - 1;
+				}
+				fixed++;
+			}
+			if (!fixed) continue;
+			attrs.forEach((/** @type {any} */ attr, /** @type {number} */ j) => attr.setArray(new (attr.getArray().constructor)(arrays[j])));
+			I.setArray(new Uint32Array(idx));
+		}
+	return { zero, flipped: fixed };
+}
+
+/**
+ * FLAT FOR SYNC (props-kit, interior-kit): every mesh node a direct child of the scene, one primitive
+ * per mesh. Core's scene sync (commandsHandler sendObject) sends a leaf mesh with its LOCAL pose but a
+ * nested Group / Object3D-with-children with its WORLD pose, which the receiver then parents under the
+ * import root — so on a peer every nested level adds the object's position again (measured: a placed
+ * Rug sat 2× its drop offset away on peer B). GLTFLoader turns a multi-primitive mesh into a Group, so
+ * primitives are split to one mesh each; flatten() lifts nested nodes to the scene with baked transforms.
+ * @param {any} doc
+ */
+export async function flatForSync(doc) {
+	await doc.transform(flatten());
+	const root = doc.getRoot();
+	const scene = root.getDefaultScene() ?? root.listScenes()[0];
+	for (const node of [...scene.listChildren()]) {
+		const mesh = node.getMesh();
+		if (!mesh || mesh.listPrimitives().length < 2) continue;
+		mesh.listPrimitives().forEach((/** @type {any} */ prim, /** @type {number} */ i) => {
+			const name = `${node.getName()}_${prim.getMaterial()?.getName() || i}`;
+			const part = doc.createNode(name).setTranslation(node.getTranslation()).setRotation(node.getRotation()).setScale(node.getScale());
+			part.setMesh(doc.createMesh(name).addPrimitive(prim));
+			scene.addChild(part);
+		});
+		node.dispose();
+		mesh.dispose();
+	}
+	await doc.transform(prune());
+}
diff --git a/tools/kit-build/lib/report.mjs b/tools/kit-build/lib/report.mjs
new file mode 100644
index 0000000..21717f1
--- /dev/null
+++ b/tools/kit-build/lib/report.mjs
@@ -0,0 +1,70 @@
+// report: the check's findings for a terminal and a GitHub step summary, and the BUDGET REPORT —
+// every item against its category budget, its bytes, textures, LOD levels and z-fight area.
+
+/** @param {any[]} findings @returns {number} errors that are not allow-listed */
+export function printFindings(findings) {
+	const order = { error: 0, warn: 1 };
+	const sorted = [...findings].sort((a, b) => (a.allowed ? 1 : 0) - (b.allowed ? 1 : 0) || order[a.level] - order[b.level] || a.pack.localeCompare(b.pack) || a.item.localeCompare(b.item));
+	let errors = 0;
+	let allowed = 0;
+	let warns = 0;
+	for (const f of sorted) {
+		const where = `${f.pack}/${f.item}`.padEnd(34);
+		if (f.allowed) {
+			allowed++;
+			if (process.env.KIT_VERBOSE) console.log(`allowed ${where} [${f.check}] ${f.msg}\n        ↳ ${f.allowed}`);
+		} else if (f.level === 'error') {
+			errors++;
+			console.log(`ERROR   ${where} [${f.check}] ${f.msg}`);
+		} else {
+			warns++;
+			console.log(`warn    ${where} [${f.check}] ${f.msg}`);
+		}
+	}
+	console.log(`\n${errors} error(s), ${warns} warning(s), ${allowed} allow-listed (KIT_VERBOSE=1 lists them with their reasons)`);
+	return errors;
+}
+
+/** markdown for $GITHUB_STEP_SUMMARY @param {{findings: any[], items: any[]}} r */
+export function summaryMarkdown(r) {
+	const errors = r.findings.filter((f) => f.level === 'error' && !f.allowed);
+	const warns = r.findings.filter((f) => f.level === 'warn');
+	const allowed = r.findings.filter((f) => f.allowed);
+	const row = (/** @type {any} */ f) => `| ${f.pack} | ${f.item} | ${f.check} | ${String(f.msg).replace(/\|/g, '\\|')} |`;
+	const lines = [
+		`## Pack checks — ${errors.length ? `❌ ${errors.length} error(s)` : '✅ pass'}`,
+		'',
+		`${r.items.length} items · ${errors.length} errors · ${warns.length} warnings · ${allowed.length} allow-listed`,
+		''
+	];
+	if (errors.length) lines.push('| pack | item | check | problem |', '|---|---|---|---|', ...errors.map(row), '');
+	if (warns.length) lines.push('<details><summary>warnings</summary>', '', '| pack | item | check | note |', '|---|---|---|---|', ...warns.map(row), '', '</details>', '');
+	if (allowed.length)
+		lines.push('<details><summary>allow-listed</summary>', '', '| pack | item | check | reason |', '|---|---|---|---|', ...allowed.map((f) => `| ${f.pack} | ${f.item} | ${f.check} | ${String(f.allowed).replace(/\|/g, '\\|')} |`), '', '</details>', '');
+	return lines.join('\n') + '\n';
+}
+
+/** the budget report @param {{findings: any[], items: any[]}} r */
+export function budgetMarkdown(r) {
+	const out = ['# Pack budget report', '', 'LOD0 triangles against the item\'s category budget (tools/kit-build/packs.json), bytes, largest texture, LOD levels (triangles), static z-fight area.', ''];
+	const byPack = new Map();
+	for (const it of r.items) {
+		if (!byPack.has(it.pack)) byPack.set(it.pack, []);
+		byPack.get(it.pack).push(it);
+	}
+	for (const [pack, items] of byPack) {
+		const tris = items.reduce((/** @type {number} */ s, /** @type {any} */ i) => s + i.tris, 0);
+		const bytes = items.reduce((/** @type {number} */ s, /** @type {any} */ i) => s + i.bytes + i.lods.reduce((/** @type {number} */ a, /** @type {any} */ l) => a + l.bytes, 0), 0);
+		const errs = r.findings.filter((f) => f.pack === pack && f.level === 'error' && !f.allowed).length;
+		out.push(`## ${pack} — ${items.length} items, ${(bytes / 1048576).toFixed(1)} MiB, ${tris.toLocaleString('en')} LOD0 triangles${errs ? `, **${errs} errors**` : ''}`, '');
+		out.push('| item | category | tris / budget | MiB | texture | LODs | z-fight cm² |', '|---|---|---|---|---|---|---|');
+		for (const i of items) {
+			const pct = i.budget ? Math.round((100 * i.tris) / i.budget) : 0;
+			const tex = Math.max(0, ...i.textures.map((/** @type {any} */ t) => Math.max(...(t.size ?? [0]))));
+			const lods = i.lods.length ? i.lods.map((/** @type {any} */ l) => l.tris).join(' / ') : '—';
+			out.push(`| ${i.item} | ${i.category ?? '?'} | ${i.tris} / ${i.budget ?? '?'} (${pct} %) | ${(i.bytes / 1048576).toFixed(2)} | ${tex || '—'} | ${lods} | ${i.flickerCm2 ?? '—'} |`);
+		}
+		out.push('');
+	}
+	return out.join('\n') + '\n';
+}
diff --git a/tools/kit-build/lib/rules.mjs b/tools/kit-build/lib/rules.mjs
new file mode 100644
index 0000000..b9b078d
--- /dev/null
+++ b/tools/kit-build/lib/rules.mjs
@@ -0,0 +1,164 @@
+// rules: the pure halves of the pack checks (no file access) — what a row, a pivot, a behavior or a
+// LOD list must look like. check.mjs feeds them measured numbers; test/rules.test.mjs proves each one
+// red on a bad input.
+
+/** core's behaviorCore.js enums (33 P2) — kept in step by hand; a new type needs core first */
+export const BEHAVIOR_TYPES = ['door', 'toggle', 'oneshot', 'loop'];
+export const BEHAVIOR_TRIGGERS = ['click', 'proximity', 'knock'];
+const BEHAVIOR_KEYS = ['type', 'clip', 'closeClip', 'trigger', 'autoplay', 'sound', 'collider'];
+/** core lodGroupCore MAX_LEVELS is 6 (LOD0 + 5 files) */
+export const MAX_LOD_FILES = 5;
+const ROW_KEYS = ['name', 'label', 'screenshot', 'variants', 'lods', 'behavior'];
+const INDEX_KEYS = ['name', 'title', 'value', 'zip', 'attribution', 'copyright', 'license', 'source', 'cover'];
+export const PIVOTS = ['bottom-center', 'bottom-center-back', 'top-center', 'wall-pivot', 'wall-face', 'foot', 'hinge', 'any'];
+
+/** a repo-relative path that stays inside its folder @param {any} p */
+export const safeRel = (p) => typeof p === 'string' && p.trim() !== '' && !p.includes('..') && !p.startsWith('/') && !/^[a-z]+:/i.test(p);
+const isUrl = (/** @type {any} */ p) => typeof p === 'string' && /^https?:\/\//.test(p);
+
+/**
+ * One index.json row. @param {any} row @returns {string[]} problems
+ */
+export function indexRowProblems(row) {
+	const out = [];
+	if (!row || typeof row !== 'object') return ['not an object'];
+	if (typeof row.name !== 'string' || !/^[a-z0-9_-]+$/i.test(row.name)) out.push('name must be a folder-safe string');
+	if (typeof row.title !== 'string' || !row.title.trim()) out.push('title missing');
+	if (!!row.value === !!row.zip) out.push('needs exactly one of value | zip');
+	for (const k of ['value', 'attribution', 'cover']) if (row[k] !== undefined && !safeRel(row[k]) && !isUrl(row[k])) out.push(`${k} must be a repo-relative path or an https URL`);
+	if (row.zip !== undefined && typeof row.zip !== 'string') out.push('zip must be a path');
+	if (typeof row.attribution !== 'string') out.push('attribution missing');
+	for (const k of ['copyright', 'license']) if (typeof row[k] !== 'string') out.push(`${k} must be a string ("" when none)`);
+	if (!isUrl(row.source)) out.push('source must be an https URL');
+	for (const k of Object.keys(row)) if (!INDEX_KEYS.includes(k)) out.push(`unknown key "${k}"`);
+	return out;
+}
+
+/**
+ * One item row of a pack's model list (default.json). Shape only; files are check.mjs's.
+ * @param {any} row @returns {string[]}
+ */
+export function itemRowProblems(row) {
+	const out = [];
+	if (!row || typeof row !== 'object') return ['not an object'];
+	if (typeof row.name !== 'string' || !/^[A-Za-z0-9_-]+$/.test(row.name)) out.push('name must be a folder-safe string');
+	if (row.label !== undefined && typeof row.label !== 'string') out.push('label must be a string');
+	if (row.screenshot !== undefined && !safeRel(row.screenshot) && !isUrl(row.screenshot)) out.push('screenshot must be a relative path or an https URL');
+	const glb = row.variants?.['glTF-Binary'];
+	if (typeof glb !== 'string' || !(safeRel(glb) || isUrl(glb))) out.push('variants["glTF-Binary"] must be a file name or an https URL');
+	else if (!isUrl(glb) && !/\.glb$/i.test(glb)) out.push('variants["glTF-Binary"] must be a .glb');
+	if (row.lods !== undefined) out.push(...lodsProblems(row.lods));
+	if (row.behavior !== undefined) out.push(...behaviorProblems(row.behavior));
+	for (const k of Object.keys(row)) if (!ROW_KEYS.includes(k)) out.push(`unknown key "${k}"`);
+	return out;
+}
+
+/**
+ * The `lods` field (contract P1): [{file, ratio}], finest first. Core silently DROPS a bad entry,
+ * so the CI is strict where the app is lenient. @param {any} lods @returns {string[]}
+ */
+export function lodsProblems(lods) {
+	if (!Array.isArray(lods) || !lods.length) return ['lods must be a non-empty array'];
+	const out = [];
+	if (lods.length > MAX_LOD_FILES) out.push(`lods: at most ${MAX_LOD_FILES} files (core draws LOD0 + ${MAX_LOD_FILES})`);
+	let prev = 1;
+	lods.forEach((l, i) => {
+		if (!l || typeof l !== 'object') return out.push(`lods[${i}] is not an object`);
+		if (!safeRel(l.file) || !/\.glb$/i.test(l.file) || l.file.includes('/')) out.push(`lods[${i}].file must be a .glb beside LOD0 (no folders, no ..)`);
+		if (typeof l.ratio !== 'number' || !(l.ratio > 0 && l.ratio <= 1)) out.push(`lods[${i}].ratio must be a number in (0, 1]`);
+		else if (l.ratio > prev) out.push(`lods[${i}].ratio ${l.ratio} is coarser-first: list levels finest first`);
+		else prev = l.ratio;
+		for (const k of Object.keys(l)) if (k !== 'file' && k !== 'ratio') out.push(`lods[${i}]: unknown key "${k}"`);
+	});
+	return out;
+}
+
+/**
+ * The `behavior` field (33 P2). Core normalizes (an unknown trigger becomes 'click', an autoplay on a
+ * door is ignored); the CI refuses instead, so a typo cannot ship as a silent default.
+ * @param {any} b @returns {string[]}
+ */
+export function behaviorProblems(b) {
+	if (!b || typeof b !== 'object' || Array.isArray(b)) return ['behavior must be an object'];
+	const out = [];
+	if (!BEHAVIOR_TYPES.includes(b.type)) out.push(`behavior.type must be one of ${BEHAVIOR_TYPES.join('|')}`);
+	if (typeof b.clip !== 'string' || !b.clip.trim() || b.clip.length > 64) out.push('behavior.clip must be a clip name (1-64 chars)');
+	if (b.trigger !== undefined && !BEHAVIOR_TRIGGERS.includes(b.trigger)) out.push(`behavior.trigger must be one of ${BEHAVIOR_TRIGGERS.join('|')}`);
+	if (b.autoplay !== undefined && typeof b.autoplay !== 'boolean') out.push('behavior.autoplay must be true or false');
+	if (b.autoplay === true && b.type !== 'loop') out.push('behavior.autoplay is only for type "loop" (nothing else plays on placement)');
+	if (b.closeClip !== undefined) {
+		if (b.type !== 'door' && b.type !== 'toggle') out.push('behavior.closeClip is only for door / toggle');
+		else if (typeof b.closeClip !== 'string' || !b.closeClip.trim()) out.push('behavior.closeClip must be a clip name');
+		else if (b.closeClip === b.clip) out.push('behavior.closeClip equals clip (leave it out to play clip backwards)');
+	}
+	if (b.sound !== undefined && (typeof b.sound !== 'string' || !b.sound.trim())) out.push('behavior.sound must be a game-sound name');
+	if (b.collider !== undefined && b.collider !== 'follow') out.push('behavior.collider must be "follow" (or absent)');
+	for (const k of Object.keys(b)) if (!BEHAVIOR_KEYS.includes(k)) out.push(`behavior: unknown key "${k}"`);
+	return out;
+}
+
+/** the clips a behavior needs, all present in the GLB? @param {any} b @param {string[]} clips */
+export function behaviorClipProblems(b, clips) {
+	const out = [];
+	for (const k of ['clip', 'closeClip']) if (typeof b?.[k] === 'string' && !clips.includes(b[k])) out.push(`behavior.${k} "${b[k]}" is not a clip of the GLB (has: ${clips.join(', ') || 'none'})`);
+	return out;
+}
+
+/** tolerance: absolute floor or a share of the extent, whichever is larger */
+const tol = (/** @type {number} */ extent, /** @type {number} */ share, /** @type {number} */ floor) => Math.max(floor, share * extent);
+
+/**
+ * Where the origin sits in the bbox, per axis. centre: within max(3 cm, 10 % of the extent) of the
+ * middle; a face: within max(2 cm, 2 %) of it.
+ * @param {number[]} min @param {number[]} max
+ */
+export function pivotOf(min, max) {
+	/** @param {number} i */
+	const axis = (i) => {
+		const e = max[i] - min[i];
+		const c = (min[i] + max[i]) / 2;
+		const f = tol(e, 0.02, 0.02);
+		return { centre: Math.abs(c) <= tol(e, 0.1, 0.03), min: Math.abs(min[i]) <= f, max: Math.abs(max[i]) <= f, above: min[i] >= -f, inside: min[i] <= 0.05 && max[i] >= -0.05 };
+	};
+	return { x: axis(0), y: axis(1), z: axis(2) };
+}
+
+/**
+ * Does the bbox satisfy the declared pivot rule? @param {number[]} min @param {number[]} max
+ * @param {string} rule @returns {string | null} what is wrong, null when it holds
+ */
+export function pivotProblem(min, max, rule) {
+	const p = pivotOf(min, max);
+	const at = `bbox x ${min[0].toFixed(2)}..${max[0].toFixed(2)}, y ${min[1].toFixed(2)}..${max[1].toFixed(2)}, z ${min[2].toFixed(2)}..${max[2].toFixed(2)}`;
+	switch (rule) {
+		case 'any':
+			return null;
+		case 'bottom-center':
+			return p.x.centre && p.z.centre && p.y.min ? null : `pivot is not bottom-centre (${at})`;
+		case 'bottom-center-back':
+			return p.x.centre && p.z.min && p.y.min ? null : `pivot is not bottom-centre-back (${at})`;
+		case 'top-center':
+			return p.x.centre && p.z.centre && p.y.max ? null : `pivot is not top-centre (${at})`;
+		case 'wall-pivot':
+			return p.x.centre && p.z.centre && p.y.above ? null : `pivot is not the wall's bottom-centre (${at})`;
+		case 'wall-face':
+			return p.x.centre && p.y.above && min[2] >= -0.02 && min[2] <= 0.3 ? null : `pivot is not on the wall line behind the piece (${at})`;
+		case 'foot':
+			return p.y.min && min[0] <= 0 && max[0] >= 0 && min[2] <= 0 && max[2] >= 0 ? null : `pivot is not under the piece (${at})`;
+		case 'hinge':
+			return p.x.inside && p.y.inside && p.z.inside ? null : `the hinge pivot is outside the piece (${at})`;
+	}
+	return `unknown pivot rule "${rule}" (one of ${PIVOTS.join('|')})`;
+}
+
+/**
+ * Scale sanity: the bbox is in METRES — a piece exported in centimetres is 100× too big, one in
+ * kilometres a speck. @param {number[]} size @param {number} maxExtent @param {number} minExtent
+ */
+export function scaleProblem(size, maxExtent, minExtent) {
+	if (!size.every(Number.isFinite)) return 'bbox is not finite';
+	const big = Math.max(...size);
+	if (big < minExtent) return `largest extent ${big.toFixed(3)} m is under ${minExtent} m — exported in km, or empty?`;
+	if (big > maxExtent) return `largest extent ${big.toFixed(2)} m is over the category's ${maxExtent} m — exported in cm?`;
+	return null;
+}
diff --git a/tools/kit-build/packs.json b/tools/kit-build/packs.json
new file mode 100644
index 0000000..a132daf
--- /dev/null
+++ b/tools/kit-build/packs.json
@@ -0,0 +1,390 @@
+{
+	"note": "kit-build's per-pack policy (roadmap 34 E2). categories: triangle budget of LOD0 (drawn, per node) and the largest bbox extent in metres. packs: textureCap (largest texture side), emissive ('none' = nothing in the pack may glow, 'allowed'), the default category and pivot, and per-item overrides. Pivots: bottom-center | bottom-center-back | top-center | wall-pivot (shares the wall's bottom-centre origin, starts above the floor) | wall-face (origin on the wall line, piece on the wall's face) | foot (stands on its origin, which is under the piece but not its middle: a signpost's post, a pipe's open end) | hinge (origin within 5 cm of the piece: a moving part) | any (legacy packs that keep their source scene's coordinates).",
+	"limits": {
+		"glbFailBytes": 5242880,
+		"glbWarnBytes": 2097152,
+		"lodRequiredOver": 2000,
+		"minExtent": 0.05,
+		"flickerCm2": 1,
+		"thumbMinPx": 64
+	},
+	"categories": {
+		"tile": {
+			"tris": 2500,
+			"maxExtent": 8.5,
+			"about": "floor / road / path tiles, rugs, flat terrain"
+		},
+		"prop": {
+			"tris": 6000,
+			"maxExtent": 4,
+			"about": "furniture, dressing, small structures"
+		},
+		"modular": {
+			"tris": 6500,
+			"maxExtent": 10,
+			"about": "snap-together building pieces: walls, posts, stairs, towers"
+		},
+		"functional": {
+			"tris": 7000,
+			"maxExtent": 5,
+			"about": "animated items with a behavior (doors, gates, lids)"
+		},
+		"hero": {
+			"tris": 8000,
+			"maxExtent": 3,
+			"about": "showcase props, few per scene"
+		},
+		"set": {
+			"tris": 12000,
+			"maxExtent": 6,
+			"about": "kitbashed groups (a crate stack, a pond set)"
+		},
+		"tree": {
+			"tris": 15000,
+			"maxExtent": 12,
+			"about": "trees"
+		},
+		"legacy": {
+			"tris": 25000,
+			"maxExtent": 10,
+			"about": "the starter packs from before the kits (default, cube_diorama)"
+		}
+	},
+	"packs": {
+		"default": {
+			"textureCap": 1024,
+			"emissive": "allowed",
+			"category": "legacy",
+			"pivot": "any"
+		},
+		"cube_diorama": {
+			"textureCap": 2048,
+			"emissive": "none",
+			"category": "legacy",
+			"pivot": "any"
+		},
+		"nature-kit": {
+			"textureCap": 1024,
+			"emissive": "none",
+			"category": "prop",
+			"pivot": "bottom-center",
+			"items": {
+				"Oak": {
+					"category": "tree"
+				},
+				"OakAutumn": {
+					"category": "tree"
+				},
+				"Pine": {
+					"category": "tree"
+				},
+				"Birch": {
+					"category": "tree"
+				},
+				"DeadTree": {
+					"category": "tree"
+				},
+				"Palm": {
+					"category": "tree"
+				},
+				"PondSet": {
+					"category": "set"
+				},
+				"BoulderCluster": {
+					"category": "set"
+				},
+				"FlowerPatch": {
+					"category": "set"
+				},
+				"PathTile": {
+					"category": "tile"
+				},
+				"FallenLeaves": {
+					"category": "tile"
+				},
+				"PondWater": {
+					"category": "tile"
+				},
+				"Hill": {
+					"category": "tile"
+				},
+				"SteppingStones": {
+					"category": "set"
+				},
+				"Cliff": {
+					"category": "modular",
+					"pivot": "bottom-center-back"
+				},
+				"Bridge": {
+					"category": "modular"
+				}
+			}
+		},
+		"architecture-kit": {
+			"textureCap": 1024,
+			"emissive": "none",
+			"category": "modular",
+			"pivot": "bottom-center",
+			"items": {
+				"FloorStone": {
+					"category": "tile"
+				},
+				"FloorWood": {
+					"category": "tile"
+				},
+				"FloorSlate": {
+					"category": "tile"
+				},
+				"Window": {
+					"pivot": "wall-pivot"
+				}
+			}
+		},
+		"props-kit": {
+			"textureCap": 1024,
+			"emissive": "allowed",
+			"category": "prop",
+			"pivot": "bottom-center",
+			"items": {
+				"CrateStack": {
+					"category": "set"
+				},
+				"Rug": {
+					"category": "tile"
+				},
+				"Hatch": {
+					"pivot": "bottom-center-back"
+				},
+				"Tapestry": {
+					"pivot": "bottom-center-back"
+				},
+				"WallButton": {
+					"pivot": "bottom-center-back"
+				},
+				"WallTorch": {
+					"pivot": "bottom-center-back"
+				},
+				"LeverHandle": {
+					"pivot": "hinge"
+				},
+				"Signpost": {
+					"pivot": "foot"
+				}
+			}
+		},
+		"scifi-kit": {
+			"textureCap": 1024,
+			"emissive": "allowed",
+			"category": "modular",
+			"pivot": "bottom-center",
+			"items": {
+				"FloorPlate": {
+					"category": "tile"
+				},
+				"FloorGrate": {
+					"category": "tile"
+				},
+				"CeilingLight": {
+					"category": "tile"
+				},
+				"Console": {
+					"category": "prop"
+				},
+				"ServerRack": {
+					"category": "prop"
+				},
+				"Crate": {
+					"category": "prop"
+				},
+				"CrateLarge": {
+					"category": "prop"
+				},
+				"Canister": {
+					"category": "prop"
+				},
+				"Chair": {
+					"category": "prop"
+				},
+				"Desk": {
+					"category": "prop"
+				},
+				"PlantPod": {
+					"category": "prop"
+				},
+				"TeleportPad": {
+					"category": "prop"
+				},
+				"Drone": {
+					"category": "prop"
+				},
+				"Lamp": {
+					"category": "prop"
+				},
+				"PipeElbow": {
+					"pivot": "foot"
+				},
+				"Vent": {
+					"pivot": "wall-face"
+				},
+				"WallScreen": {
+					"pivot": "wall-face"
+				}
+			}
+		},
+		"interactive-kit": {
+			"textureCap": 1024,
+			"emissive": "allowed",
+			"category": "functional",
+			"pivot": "bottom-center",
+			"items": {
+				"Shutters": {
+					"pivot": "wall-pivot"
+				},
+				"Banner": {
+					"pivot": "bottom-center-back"
+				},
+				"Torch": {
+					"pivot": "bottom-center-back"
+				},
+				"WallButton": {
+					"pivot": "bottom-center-back"
+				},
+				"CeilingFan": {
+					"pivot": "top-center"
+				},
+				"Lever": {
+					"pivot": "hinge"
+				}
+			}
+		},
+		"interior-kit": {
+			"textureCap": 1024,
+			"emissive": "allowed",
+			"category": "prop",
+			"pivot": "bottom-center",
+			"items": {
+				"TavernTableSet": {
+					"category": "set"
+				},
+				"DiningSet": {
+					"category": "set"
+				},
+				"RugRound": {
+					"category": "tile"
+				},
+				"BackBar": {
+					"pivot": "wall-face"
+				},
+				"Cornice": {
+					"pivot": "wall-face"
+				},
+				"DoubleBed": {
+					"pivot": "wall-face"
+				},
+				"Fireplace": {
+					"pivot": "wall-face"
+				},
+				"KitchenCounter": {
+					"pivot": "wall-face"
+				},
+				"Picture": {
+					"pivot": "wall-face"
+				},
+				"Skirting": {
+					"pivot": "wall-face"
+				},
+				"SkirtingDoorway": {
+					"pivot": "wall-face"
+				},
+				"Stove": {
+					"pivot": "wall-face"
+				},
+				"Wainscot": {
+					"pivot": "wall-face"
+				},
+				"WainscotDoorway": {
+					"pivot": "wall-face"
+				},
+				"WallSconce": {
+					"pivot": "wall-face"
+				},
+				"WallShelfBooks": {
+					"pivot": "wall-face"
+				},
+				"Wardrobe": {
+					"pivot": "wall-face"
+				},
+				"Chandelier": {
+					"pivot": "top-center"
+				}
+			}
+		},
+		"town-kit": {
+			"textureCap": 1024,
+			"emissive": "allowed",
+			"category": "prop",
+			"pivot": "bottom-center",
+			"items": {
+				"Road": {
+					"category": "tile"
+				},
+				"RoadCurb": {
+					"category": "tile"
+				},
+				"RoadCorner": {
+					"category": "tile"
+				},
+				"RoadCrossing": {
+					"category": "tile"
+				},
+				"Sidewalk": {
+					"category": "tile"
+				},
+				"StoneStairs": {
+					"category": "modular"
+				},
+				"ClockTowerTop": {
+					"category": "modular"
+				},
+				"Bridge": {
+					"category": "modular"
+				},
+				"Fence": {
+					"category": "modular"
+				},
+				"FenceGate": {
+					"category": "functional"
+				},
+				"LoadedCart": {
+					"category": "set"
+				},
+				"BarrelCluster": {
+					"category": "set",
+					"pivot": "foot"
+				},
+				"SacksBarrel": {
+					"category": "set"
+				},
+				"Banner": {
+					"pivot": "wall-face"
+				},
+				"Signpost": {
+					"pivot": "foot"
+				}
+			}
+		},
+		"arcane-kit": {
+			"textureCap": 1024,
+			"emissive": "allowed",
+			"category": "hero",
+			"pivot": "bottom-center"
+		},
+		"khronos-sample-assets": {
+			"textureCap": 4096,
+			"emissive": "allowed",
+			"category": "legacy",
+			"pivot": "any",
+			"about": "upstream-fetch: every row is an absolute URL into KhronosGroup/glTF-Sample-Assets, no bytes here"
+		}
+	}
+}
diff --git a/tools/kit-build/test/check.test.mjs b/tools/kit-build/test/check.test.mjs
new file mode 100644
index 0000000..8d511fc
--- /dev/null
+++ b/tools/kit-build/test/check.test.mjs
@@ -0,0 +1,235 @@
+// kit-build check: the fixture pack passes, and every check goes RED when its one thing is broken
+// (the counterfactual per guard). No browser, no network.
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import fs from 'node:fs';
+import path from 'node:path';
+import { runChecks } from '../lib/check.mjs';
+import { passPack } from '../lib/pass.mjs';
+import { fixture, boxGlb, errorsOf } from './fixture.mjs';
+
+/** run the checks on a fixture and return its unallowed errors @param {(f: any) => any} [edit] */
+async function errors(edit) {
+	const dir = await fixture(edit);
+	try {
+		return errorsOf(await runChecks(dir));
+	} finally {
+		fs.rmSync(dir, { recursive: true, force: true });
+	}
+}
+const has = (/** @type {string[]} */ errs, /** @type {string} */ check, /** @type {RegExp} */ re) =>
+	assert.ok(errs.some((e) => e.startsWith(`${check}:`) && re.test(e)), `expected a ${check} error matching ${re}, got:\n${errs.join('\n') || '(none)'}`);
+
+test('the fixture pack passes every check', async () => {
+	assert.deepEqual(await errors(), []);
+});
+
+test('index: a row without a source URL, and a value file that does not exist', async () => {
+	const e = await errors((f) => {
+		delete f.index[0].source;
+		f.index.push({ ...f.index[0], name: 'ghost', value: 'ghost/default.json', source: 'https://x.y' });
+	});
+	has(e, 'index', /source must be an https URL/);
+	has(e, 'index', /ghost\/default.json does not exist/);
+});
+
+test('manifest: an unknown row key (a typo) and a duplicate item', async () => {
+	const e = await errors((f) => {
+		f.rows[0].lable = 'typo';
+		f.rows.push({ ...f.rows[0] });
+	});
+	has(e, 'manifest', /unknown key "lable"/);
+	has(e, 'manifest', /duplicate item name/);
+});
+
+test('size: a GLB over the share cap', async () => {
+	has(await errors((f) => (f.limits.glbFailBytes = 1000)), 'size', /over the 5 MiB share cap/);
+});
+
+test('tris: LOD0 over its category budget', async () => {
+	has(await errors((f) => (f.categories.prop.tris = 10)), 'tris', /12 triangles is over the prop budget of 10/);
+});
+
+test('textures: a texture over the pack cap', async () => {
+	has(await errors(async (f) => (f.files['kit/Box/glTF-Binary/box.glb'] = await boxGlb({ texture: 2048 }))), 'textures', /2048² texture is over the pack's 1024 cap/);
+});
+
+test('emissive: a glowing material in a "nothing glows" pack', async () => {
+	const e = await errors(async (f) => {
+		f.policy.emissive = 'none';
+		f.files['kit/Box/glTF-Binary/box.glb'] = await boxGlb({ emissive: true });
+	});
+	has(e, 'emissive', /policy is "nothing glows"/);
+});
+
+test('scale: a box exported in centimetres', async () => {
+	has(await errors(async (f) => (f.files['kit/Box/glTF-Binary/box.glb'] = await boxGlb({ scale: 100 }))), 'scale', /exported in cm/);
+});
+
+test('pivot: a box whose origin is off to the side (and the declared exception lets a wall piece through)', async () => {
+	has(await errors(async (f) => (f.files['kit/Box/glTF-Binary/box.glb'] = await boxGlb({ offset: [2, 0, 0] }))), 'pivot', /not bottom-centre/);
+	assert.deepEqual(
+		await errors(async (f) => {
+			f.files['kit/Box/glTF-Binary/box.glb'] = await boxGlb({ offset: [0, 1, 0] });
+			f.policy.items = { Box: { pivot: 'wall-pivot' } };
+		}),
+		[]
+	);
+});
+
+test('lods: required over the floor; a missing file; a wrong ratio; a level with foreign node names; a level without the clips', async () => {
+	has(await errors((f) => (f.limits.lodRequiredOver = 5)), 'lods', /no LOD files/);
+	has(await errors((f) => (f.rows[0].lods = [{ file: 'box.lod1.glb', ratio: 0.67 }])), 'lods', /box.lod1.glb does not exist/);
+	has(
+		await errors(async (f) => {
+			f.rows[0].lods = [{ file: 'box.lod1.glb', ratio: 0.3 }];
+			f.files['kit/Box/glTF-Binary/box.lod1.glb'] = await boxGlb({ faces: 4 });
+		}),
+		'lods',
+		/ratio 0.3 but the file has 67 %/
+	);
+	assert.deepEqual(
+		await errors(async (f) => {
+			f.rows[0].lods = [{ file: 'box.lod1.glb', ratio: 0.67 }];
+			f.files['kit/Box/glTF-Binary/box.lod1.glb'] = await boxGlb({ faces: 4 });
+		}),
+		[],
+		'a right level passes'
+	);
+	has(
+		await errors(async (f) => {
+			// LOD0 draws two nodes; the level one, under a name LOD0 does not have (core cannot match it)
+			f.rows[0].lods = [{ file: 'box.lod1.glb', ratio: 0.33 }];
+			f.files['kit/Box/glTF-Binary/box.glb'] = await boxGlb({ twin: 'Lid' });
+			f.files['kit/Box/glTF-Binary/box.lod1.glb'] = await boxGlb({ faces: 4, nodeName: 'Other' });
+		}),
+		'lods',
+		/BY NODE NAME|has mesh nodes LOD0 does not/
+	);
+	has(
+		await errors(async (f) => {
+			f.rows[0].lods = [{ file: 'box.lod1.glb', ratio: 0.67 }];
+			f.files['kit/Box/glTF-Binary/box.glb'] = await boxGlb({ clips: ['open'] });
+			f.files['kit/Box/glTF-Binary/box.lod1.glb'] = await boxGlb({ faces: 4 });
+		}),
+		'lods',
+		/lacks LOD0's clips open/
+	);
+});
+
+test('behavior: a clip the GLB does not have; a door that autoplays', async () => {
+	const door = { type: 'door', clip: 'open', trigger: 'click' };
+	assert.deepEqual(
+		await errors(async (f) => {
+			f.rows[0].behavior = door;
+			f.files['kit/Box/glTF-Binary/box.glb'] = await boxGlb({ clips: ['open'] });
+		}),
+		[]
+	);
+	has(await errors((f) => (f.rows[0].behavior = door)), 'behavior', /"open" is not a clip of the GLB/);
+	has(await errors((f) => (f.rows[0].behavior = { ...door, autoplay: true })), 'manifest', /autoplay is only for type "loop"/);
+});
+
+test('flicker: a decal lying ON a face fails; its recorded baseline lets it through; worse than the baseline fails', async () => {
+	const decal = async (/** @type {any} */ f) => (f.files['kit/Box/glTF-Binary/box.glb'] = await boxGlb({ coplanar: true }));
+	has(await errors(decal), 'flicker', /coplanar pairs, 3600\.0 cm² of overlap/);
+	const file = 'kit/Box/glTF-Binary/box.glb';
+	assert.deepEqual(await errors(async (f) => (await decal(f), (f.baseline[file] = { cm2: 3600, pairs: 2, px: 10, why: 'test' }))), []);
+	has(await errors(async (f) => (await decal(f), (f.baseline[file] = { cm2: 100, pairs: 2, px: 10, why: 'test' }))), 'flicker', /WORSE than its baseline/);
+});
+
+test('thumb: a row whose screenshot is missing, or too small', async () => {
+	has(await errors((f) => delete f.files['kit/Box/thumb.webp']), 'thumb', /no thumbnail/);
+	has(await errors((f) => (f.limits.thumbMinPx = 256)), 'thumb', /\(< 256 px\)/);
+});
+
+test('allow-list: a listed failure is accepted with its reason; an entry that matches nothing warns', async () => {
+	const dir = await fixture((f) => {
+		f.categories.prop.tris = 10;
+		f.allow = [
+			{ pack: 'kit', item: 'Box', check: 'tris', reason: 'test' },
+			{ pack: 'kit', item: 'Gone', check: 'lods', reason: 'stale' }
+		];
+	});
+	try {
+		const r = await runChecks(dir);
+		assert.deepEqual(errorsOf(r), []);
+		assert.equal(r.findings.find((x) => x.check === 'tris')?.allowed, 'test');
+		assert.ok(r.findings.some((x) => x.level === 'warn' && x.check === 'allow' && x.item === 'Gone'));
+	} finally {
+		fs.rmSync(dir, { recursive: true, force: true });
+	}
+});
+
+test('pass: fixes texture cap and emissive policy — and leaves a compliant file byte-identical', async () => {
+	const dir = await fixture(async (f) => {
+		f.policy.emissive = 'none';
+		f.files['kit/Box/glTF-Binary/box.glb'] = await boxGlb({ texture: 2048, emissive: true });
+	});
+	const glb = path.join(dir, 'kit/Box/glTF-Binary/box.glb');
+	try {
+		assert.ok(errorsOf(await runChecks(dir)).length >= 2, 'red before the pass');
+		const before = fs.readFileSync(glb);
+		assert.equal(await passPack(dir, 'kit', {}), 1, 'a dry run reports it');
+		assert.deepEqual(fs.readFileSync(glb), before, 'a dry run writes nothing');
+		assert.equal(await passPack(dir, 'kit', { write: true }), 1);
+		assert.deepEqual(errorsOf(await runChecks(dir)), [], 'green after the pass');
+		const fixed = fs.readFileSync(glb);
+		assert.equal(await passPack(dir, 'kit', { write: true }), 0, 'nothing left to do');
+		assert.deepEqual(fs.readFileSync(glb), fixed, 'and the file is not rewritten');
+	} finally {
+		fs.rmSync(dir, { recursive: true, force: true });
+	}
+});
+
+test('pass: an opaque PNG over the share cap becomes JPEG', async () => {
+	const dir = await fixture(async (f) => {
+		f.files['kit/Box/glTF-Binary/box.glb'] = await boxGlb({ png: 512 });
+		f.limits.glbFailBytes = 400_000;
+	});
+	try {
+		has(errorsOf(await runChecks(dir)), 'size', /share cap/);
+		await passPack(dir, 'kit', { write: true });
+		assert.deepEqual(errorsOf(await runChecks(dir)), []);
+	} finally {
+		fs.rmSync(dir, { recursive: true, force: true });
+	}
+});
+
+test('pass: LOD0 over its triangle budget is decimated to it (node names kept)', async () => {
+	const { load, makeIO } = await import('../lib/deps.mjs');
+	const { Document } = await load('@gltf-transform/core');
+	// a 2 × 2 m floor tile of 40 × 40 quads = 3 200 triangles, flat: meshopt can take nearly all of them
+	const doc = new Document();
+	const buf = doc.createBuffer();
+	const n = 40;
+	const P = [];
+	const I = [];
+	for (let z = 0; z <= n; z++) for (let x = 0; x <= n; x++) P.push((2 * x) / n - 1, 0, (2 * z) / n - 1);
+	for (let z = 0; z < n; z++)
+		for (let x = 0; x < n; x++) {
+			const a = z * (n + 1) + x;
+			I.push(a, a + n + 1, a + 1, a + 1, a + n + 1, a + n + 2);
+		}
+	const prim = doc
+		.createPrimitive()
+		.setAttribute('POSITION', doc.createAccessor().setType('VEC3').setArray(new Float32Array(P)).setBuffer(buf))
+		.setIndices(doc.createAccessor().setType('SCALAR').setArray(new Uint16Array(I)).setBuffer(buf))
+		.setMaterial(doc.createMaterial('M'));
+	doc.createScene('Scene').addChild(doc.createNode('Tile').setMesh(doc.createMesh('Tile').addPrimitive(prim)));
+	const tile = Buffer.from(await makeIO().writeBinary(doc));
+	const dir = await fixture((f) => {
+		f.files['kit/Box/glTF-Binary/box.glb'] = tile;
+		f.categories.prop.tris = 500;
+	});
+	try {
+		has(errorsOf(await runChecks(dir)), 'tris', /3200 triangles is over the prop budget of 500/);
+		await passPack(dir, 'kit', { write: true });
+		const r = await runChecks(dir);
+		assert.deepEqual(errorsOf(r), []);
+		assert.ok(r.items[0].tris <= 500 && r.items[0].tris > 0, `decimated to ${r.items[0].tris}`);
+		assert.deepEqual(r.items[0].meshNodes, ['Tile']);
+	} finally {
+		fs.rmSync(dir, { recursive: true, force: true });
+	}
+});
diff --git a/tools/kit-build/test/fixture.mjs b/tools/kit-build/test/fixture.mjs
new file mode 100644
index 0000000..0308fb6
--- /dev/null
+++ b/tools/kit-build/test/fixture.mjs
@@ -0,0 +1,110 @@
+// A one-pack repo in a temp folder that passes every check — each test breaks ONE thing in it.
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import { load, makeIO, REPO } from '../lib/deps.mjs';
+
+const { Document } = await load('@gltf-transform/core');
+const sharp = (await load('sharp')).default;
+
+/** the real policy file, so the categories the tests use are the shipped ones */
+export const REAL = JSON.parse(fs.readFileSync(path.join(REPO, 'tools/kit-build/packs.json'), 'utf8'));
+
+/**
+ * A box GLB: x/z -0.5..0.5, y 0..1 (bottom-centre pivot), 12 triangles, one node "Box".
+ * @param {{scale?: number, offset?: number[], faces?: number, texture?: number, emissive?: boolean,
+ *   coplanar?: boolean, clips?: string[], nodeName?: string, twin?: string, png?: number}} [o]
+ */
+export async function boxGlb(o = {}) {
+	const doc = new Document();
+	const buf = doc.createBuffer();
+	const k = o.scale ?? 1;
+	const off = o.offset ?? [0, 0, 0];
+	const P = [];
+	const I = [];
+	// six faces as quads [corner, u, v] in the unit box
+	const faces = [
+		[[0, 0, 1], [1, 0, 0], [0, 1, 0]],
+		[[1, 0, 0], [-1, 0, 0], [0, 1, 0]],
+		[[0, 0, 0], [0, 0, 1], [0, 1, 0]],
+		[[1, 0, 1], [0, 0, -1], [0, 1, 0]],
+		[[0, 1, 1], [1, 0, 0], [0, 0, -1]],
+		[[0, 0, 0], [1, 0, 0], [0, 0, 1]]
+	].slice(0, o.faces ?? 6);
+	if (o.coplanar) faces.push([[0.2, 1, 0.8], [0.6, 0, 0], [0, 0, -0.6]]); // a decal lying ON the top face
+	for (const [c, u, v] of faces) {
+		const b = P.length / 3;
+		for (const [a, bb] of [[0, 0], [1, 0], [1, 1], [0, 1]]) for (let i = 0; i < 3; i++) P.push(((c[i] + a * u[i] + bb * v[i] - (i === 1 ? 0 : 0.5)) * k) + off[i]);
+		I.push(b, b + 1, b + 2, b, b + 2, b + 3);
+	}
+	const pos = doc.createAccessor().setType('VEC3').setArray(new Float32Array(P)).setBuffer(buf);
+	const idx = doc.createAccessor().setType('SCALAR').setArray(new Uint16Array(I)).setBuffer(buf);
+	const mat = doc.createMaterial('M').setDoubleSided(true);
+	if (o.emissive) mat.setEmissiveFactor([1, 0.5, 0]);
+	let uv = null;
+	if (o.texture || o.png) {
+		const n = o.texture ?? o.png ?? 64;
+		const img = sharp({ create: { width: n, height: n, channels: 3, background: '#a08060' } });
+		// a photo-like gradient with fine grain: big as PNG, small as JPEG (the share-cap test)
+		const raw = Buffer.alloc(n * n * 3);
+		let r = 7;
+		for (let i = 0; i < raw.length; i++) {
+			r ^= r << 13; r ^= r >>> 17; r ^= r << 5;
+			raw[i] = ((((i / 3) % n) * 200) / n + (r & 15)) | 0;
+		}
+		const bytes = o.png ? await sharp(raw, { raw: { width: n, height: n, channels: 3 } }).png().toBuffer() : await img.jpeg().toBuffer();
+		mat.setBaseColorTexture(doc.createTexture('T').setImage(new Uint8Array(bytes)).setMimeType(o.png ? 'image/png' : 'image/jpeg'));
+		uv = doc.createAccessor().setType('VEC2').setArray(new Float32Array((P.length / 3) * 2)).setBuffer(buf);
+	}
+	const prim = doc.createPrimitive().setAttribute('POSITION', pos).setIndices(idx).setMaterial(mat);
+	if (uv) prim.setAttribute('TEXCOORD_0', uv);
+	const mesh = doc.createMesh('Box').addPrimitive(prim);
+	const node = doc.createNode(o.nodeName ?? 'Box').setMesh(mesh);
+	const scene = doc.createScene('Scene').addChild(node);
+	if (o.twin) scene.addChild(doc.createNode(o.twin).setMesh(mesh).setTranslation([0, 0, 0]));
+	for (const name of o.clips ?? []) {
+		const t = doc.createAccessor().setType('SCALAR').setArray(new Float32Array([0, 1])).setBuffer(buf);
+		const v = doc.createAccessor().setType('VEC3').setArray(new Float32Array([0, 0, 0, 0, 0.1, 0])).setBuffer(buf);
+		const s = doc.createAnimationSampler().setInput(t).setOutput(v).setInterpolation('LINEAR');
+		doc.createAnimation(name).addSampler(s).addChannel(doc.createAnimationChannel().setTargetNode(node).setTargetPath('translation').setSampler(s));
+	}
+	return Buffer.from(await makeIO().writeBinary(doc));
+}
+
+/**
+ * Write the fixture repo. `edit` may change {index, rows, policy, limits, allow, baseline, files}
+ * before it is written; files are {relPath: Buffer | string}.
+ * @param {(f: any) => void | Promise<void>} [edit]
+ */
+export async function fixture(edit) {
+	const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'kit-check-'));
+	const f = {
+		index: [{ name: 'kit', title: 'Kit', value: 'kit/default.json', attribution: 'kit/attribution.html', copyright: '', license: 'CC0-1.0', source: 'https://github.com/theprototype-app/packs' }],
+		rows: [{ name: 'Box', label: 'Box', screenshot: 'thumb.webp', variants: { 'glTF-Binary': 'box.glb' } }],
+		policy: { textureCap: 1024, emissive: 'allowed', category: 'prop', pivot: 'bottom-center' },
+		limits: { ...REAL.limits },
+		categories: JSON.parse(JSON.stringify(REAL.categories)),
+		allow: [],
+		baseline: {},
+		files: /** @type {Record<string, Buffer | string>} */ ({
+			'kit/attribution.html': '<p>CC0</p>',
+			'kit/Box/glTF-Binary/box.glb': await boxGlb(),
+			'kit/Box/thumb.webp': await sharp({ create: { width: 128, height: 128, channels: 3, background: '#888' } }).webp().toBuffer()
+		})
+	};
+	if (edit) await edit(f);
+	const w = (/** @type {string} */ rel, /** @type {Buffer | string} */ data) => {
+		fs.mkdirSync(path.dirname(path.join(dir, rel)), { recursive: true });
+		fs.writeFileSync(path.join(dir, rel), data);
+	};
+	w('index.json', JSON.stringify(f.index));
+	w('kit/default.json', JSON.stringify(f.rows));
+	for (const [rel, data] of Object.entries(f.files)) w(rel, data);
+	w('tools/kit-build/packs.json', JSON.stringify({ limits: f.limits, categories: f.categories, packs: { kit: f.policy } }));
+	w('tools/kit-build/allow.json', JSON.stringify({ allow: f.allow }));
+	w('tools/kit-build/flicker-baseline.json', JSON.stringify({ files: f.baseline }));
+	return dir;
+}
+
+/** the unallowed errors of a run, as "check: message" @param {any} r */
+export const errorsOf = (r) => r.findings.filter((/** @type {any} */ x) => x.level === 'error' && !x.allowed).map((/** @type {any} */ x) => `${x.check}: ${x.msg}`);
diff --git a/tools/kit-build/test/rules.test.mjs b/tools/kit-build/test/rules.test.mjs
new file mode 100644
index 0000000..9ab1d67
--- /dev/null
+++ b/tools/kit-build/test/rules.test.mjs
@@ -0,0 +1,70 @@
+// kit-build rules: the pure checks, each shown red on the input it exists to catch.
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { behaviorProblems, behaviorClipProblems, lodsProblems, itemRowProblems, indexRowProblems, pivotProblem, scaleProblem } from '../lib/rules.mjs';
+
+test('behavior: the shipped door passes; typos and rule breaks do not', () => {
+	const door = { type: 'door', clip: 'open', closeClip: 'close', trigger: 'click', autoplay: false, sound: 'door', collider: 'follow' };
+	assert.deepEqual(behaviorProblems(door), []);
+	assert.deepEqual(behaviorProblems({ type: 'loop', clip: 'spin', trigger: 'click', autoplay: true }), [], 'an ambient loop may autoplay');
+	assert.match(behaviorProblems({ ...door, type: 'dor' }).join(), /type must be one of/);
+	assert.match(behaviorProblems({ ...door, trigger: 'clik' }).join(), /trigger must be one of/, 'core would silently make it "click"');
+	assert.match(behaviorProblems({ ...door, autoplay: true }).join(), /only for type "loop"/);
+	assert.match(behaviorProblems({ ...door, closeClip: 'open' }).join(), /equals clip/);
+	assert.match(behaviorProblems({ type: 'oneshot', clip: 'x', closeClip: 'y' }).join(), /only for door \/ toggle/);
+	assert.match(behaviorProblems({ ...door, colider: 'follow' }).join(), /unknown key "colider"/);
+	assert.match(behaviorProblems({ ...door, clip: '' }).join(), /clip must be a clip name/);
+	assert.deepEqual(behaviorClipProblems(door, ['idle', 'open', 'close']), []);
+	assert.match(behaviorClipProblems(door, ['idle', 'open']).join(), /closeClip "close" is not a clip/);
+});
+
+test('lods: finest first, files beside LOD0, ratios in (0, 1]', () => {
+	assert.deepEqual(lodsProblems([{ file: 'a.lod1.glb', ratio: 0.5 }, { file: 'a.lod2.glb', ratio: 0.2 }]), []);
+	assert.match(lodsProblems([{ file: 'a.lod2.glb', ratio: 0.2 }, { file: 'a.lod1.glb', ratio: 0.5 }]).join(), /finest first/);
+	assert.match(lodsProblems([{ file: '../b/a.lod1.glb', ratio: 0.5 }]).join(), /beside LOD0/);
+	assert.match(lodsProblems([{ file: 'sub/a.lod1.glb', ratio: 0.5 }]).join(), /beside LOD0/);
+	assert.match(lodsProblems([{ file: 'a.lod1.glb', ratio: 0 }]).join(), /ratio must be a number in \(0, 1\]/);
+	assert.match(lodsProblems([{ file: 'a.lod1.glb', ratio: '0.5' }]).join(), /ratio must be a number/);
+	assert.match(lodsProblems([]).join(), /non-empty/);
+});
+
+test('rows: the shape core reads', () => {
+	const row = { name: 'WallStone', label: 'Wall', screenshot: 'screenshot/screenshot.webp', variants: { 'glTF-Binary': 'wall-stone.glb' } };
+	assert.deepEqual(itemRowProblems(row), []);
+	assert.deepEqual(itemRowProblems({ ...row, variants: { 'glTF-Binary': 'https://raw.githubusercontent.com/x/y.glb' }, screenshot: 'https://x/y.jpg' }), [], 'upstream-fetch rows');
+	assert.match(itemRowProblems({ ...row, variants: {} }).join(), /glTF-Binary/);
+	assert.match(itemRowProblems({ ...row, variants: { 'glTF-Binary': 'wall.gltf' } }).join(), /must be a .glb/);
+	assert.match(itemRowProblems({ ...row, name: 'Wall Stone' }).join(), /folder-safe/);
+	assert.match(itemRowProblems({ ...row, lod: [] }).join(), /unknown key "lod"/);
+	const idx = { name: 'kit', title: 'Kit', value: 'kit/default.json', attribution: 'kit/a.html', copyright: '', license: 'CC0-1.0', source: 'https://github.com/x' };
+	assert.deepEqual(indexRowProblems(idx), []);
+	assert.match(indexRowProblems({ ...idx, zip: 'kit/k.zip' }).join(), /exactly one of value \| zip/);
+	assert.match(indexRowProblems({ ...idx, license: undefined }).join(), /license must be a string/);
+});
+
+test('pivot rules: each preset accepts its shape and refuses an off-origin piece', () => {
+	const wall = [[-1, 0, -0.125], [1, 3, 0.125]];
+	assert.equal(pivotProblem(wall[0], wall[1], 'bottom-center'), null);
+	assert.match(String(pivotProblem([0, 0, -0.125], [2, 3, 0.125], 'bottom-center')), /not bottom-centre/, 'origin at a corner');
+	assert.match(String(pivotProblem([-1, -1.5, -0.125], [1, 1.5, 0.125], 'bottom-center')), /not bottom-centre/, 'origin in the middle of the height');
+	assert.equal(pivotProblem([-0.55, 0.97, -0.25], [0.55, 2.23, 0.25], 'wall-pivot'), null, 'a window on the wall origin');
+	assert.match(String(pivotProblem([-0.55, -0.5, -0.25], [0.55, 2.23, 0.25], 'wall-pivot')), /wall's bottom-centre/);
+	assert.equal(pivotProblem([-0.67, 0, 0], [0.67, 1.66, 0.09], 'bottom-center-back'), null, 'a tapestry');
+	assert.equal(pivotProblem([-0.46, -0.92, -0.44], [0.46, 0, 0.44], 'top-center'), null, 'a chandelier');
+	assert.match(String(pivotProblem([-0.46, 0, -0.44], [0.46, 0.92, 0.44], 'top-center')), /top-centre/);
+	assert.equal(pivotProblem([-1, 0, 0.125], [1, 0.25, 0.15], 'wall-face'), null, 'a skirting on the wall face');
+	assert.match(String(pivotProblem([-1, 0, 1.2], [1, 0.25, 1.3], 'wall-face')), /wall line/);
+	assert.equal(pivotProblem([-0.75, 0, -0.45], [0.86, 2.46, 0.79], 'foot'), null, 'a signpost on its post');
+	assert.match(String(pivotProblem([0.2, 0, 0.2], [1, 2, 1], 'foot')), /not under the piece/);
+	assert.equal(pivotProblem([-0.07, -0.03, -0.04], [0.07, 0.51, 0.04], 'hinge'), null);
+	assert.match(String(pivotProblem([1, 1, 1], [2, 2, 2], 'hinge')), /outside the piece/);
+	assert.equal(pivotProblem([5, 5, 5], [6, 6, 6], 'any'), null);
+	assert.match(String(pivotProblem(wall[0], wall[1], 'middle')), /unknown pivot rule/);
+});
+
+test('scale: metres, not centimetres or kilometres', () => {
+	assert.equal(scaleProblem([2, 3, 0.25], 10, 0.05), null);
+	assert.match(String(scaleProblem([200, 300, 25], 10, 0.05)), /exported in cm/);
+	assert.match(String(scaleProblem([0.002, 0.003, 0.0002], 10, 0.05)), /in km, or empty/);
+	assert.match(String(scaleProblem([NaN, 1, 1], 10, 0.05)), /not finite/);
+});
diff --git a/tools/lod/README.md b/tools/lod/README.md
index 5729503..1a062b8 100644
--- a/tools/lod/README.md
+++ b/tools/lod/README.md
@@ -28,7 +28,7 @@ skipped item with its reason.
   `defight-all.mjs` LOOKS at every candidate (surface rule, bbox-middle rule, drop-only) against
   the original render and keeps the one with the least overlap among those within Δ 30; none →
   the file is left as is. Every file's outcome is in `defight-report.json`. The
-  architecture/scifi kit-post runs it last (their seam clamp is what folds relief into
+  architecture/scifi post step (tools/kit-build/lib/post.mjs) runs it last (their seam clamp is what folds relief into
   coplanar layers). A kitbashed lining must never sit flush with a cut wall: scifi's
   `procedural.mjs` insets it 4 mm (`tools/scifi-kit/inset-linings.mjs` for shipped GLBs) —
   inset BEFORE defight.
diff --git a/tools/scifi-kit/build.mjs b/tools/scifi-kit/build.mjs
index fbf8697..203eb54 100644
--- a/tools/scifi-kit/build.mjs
+++ b/tools/scifi-kit/build.mjs
@@ -19,6 +19,7 @@ import path from 'node:path';
 import { createRequire } from 'node:module';
 import { fileURLToPath, pathToFileURL } from 'node:url';
 import { TOOLS, kitPost } from './kit-post.mjs';
+import { defightFile } from '../lod/defight.mjs';
 import { kitCut, DERIVE } from './kit-cut.mjs';
 import { writePiece, OPENINGS } from './procedural.mjs';
 
@@ -122,6 +123,10 @@ async function buildItem(it) {
 			report = { ...report, cut: await kitCut(cur, next, typeof it.cut === 'string' ? DERIVE[it.cut](it.cutOpts ?? OPENINGS[it.cut]) : it.cut) };
 			cur = next;
 		}
+		// a cut (mirror, opening) or a kitbash (a wall + its lining or glass) makes surfaces meet in
+		// one plane AFTER the post step's defight ran: settle them last (34-pack-ci — without this a
+		// rebuild ships 300-3000 cm² of coplanar overlap on every wall that the shipped files do not have)
+		if (it.cut || it.kitbash) await defightFile(cur, cur);
 		fs.copyFileSync(cur, out);
 		const doc = await io.read(out);
 		// FLAT for sync (props-kit finding 2): core's sendObject sends a nested node with its
diff --git a/tools/scifi-kit/kit-post.mjs b/tools/scifi-kit/kit-post.mjs
index 4445006..13d7aec 100644
--- a/tools/scifi-kit/kit-post.mjs
+++ b/tools/scifi-kit/kit-post.mjs
@@ -1,249 +1,5 @@
-// kit-post: the sci-fi kit's post step around tools/meshy's meshy-post.
-//
-//   raw Meshy GLB → pre-rotate (Meshy often lays a floor tile or roof slab upright, and
-//   meshy-post only turns about Y) → meshy-post (weld, simplify, stretch to the exact
-//   dims, pivot, 1024² JPEG) → SEAM CLAMP → pack GLB.
-//
-// The seam clamp is what makes pieces snap without gaps: Meshy's ends are never quite
-// planar (a stone sticks out 2 cm, the next one is 3 cm short), so after the stretch
-// every vertex within `eps` of a bbox face named in `clamp` is moved ONTO that face.
-// Two walls placed end to end then share one exact plane at their joint.
-//
-//   node kit-post.mjs <raw.glb> <out.glb> '<job json>'
-//   job = meshy-post's job + { preRotate?: {x?, y?, z?} degrees, clamp?: "x" | "xz" | "xyz" | "x-y" …,
-//         eps?: metres (default 0.04), offset?: [x, y, z] metres applied last,
-//         albedo?: {saturation, brightness, hue} grade of the base colour, dropEmissive?: false to keep it,
-//         glow?: {hue: [lo, hi], sat, val, strength} — light the albedo's own light strips (see glowMask),
-//         recolor?: {hue: [lo, hi], sat, val, shift} — scale saturation/value (and shift the hue) of that band only (see recolor) }
-// `clamp` lists axes; a trailing "-y" etc. means "the MIN face of y only" (a floor's bottom).
-import fs from 'node:fs';
-import os from 'node:os';
-import path from 'node:path';
-import { createRequire } from 'node:module';
-import { pathToFileURL } from 'node:url';
-import { defightFile } from '../lod/defight.mjs';
-
-export const TOOLS = process.env.MESHY_TOOLS || '/home/deck/.code/theprototype-app/packs-lane-30c-tools/tools/meshy';
-const req = createRequire(path.join(TOOLS, 'package.json'));
-const load = async (/** @type {string} */ id) => import(pathToFileURL(req.resolve(id)).href);
-
-const { NodeIO } = await load('@gltf-transform/core');
-const { ALL_EXTENSIONS, KHRMaterialsEmissiveStrength } = await load('@gltf-transform/extensions');
-const { getBounds, transformMesh, prune } = await load('@gltf-transform/functions');
-const { postProcess } = await import(pathToFileURL(path.join(TOOLS, 'lib/post.js')).href);
-const sharp = (await load('sharp')).default;
-
-const io = new NodeIO().registerExtensions(ALL_EXTENSIONS);
-const AX = { x: 0, y: 1, z: 2 };
-
-/** column-major 4x4 rotation about one axis @param {'x'|'y'|'z'} axis @param {number} deg */
-function rot(axis, deg) {
-	const a = (deg * Math.PI) / 180;
-	const c = Math.cos(a);
-	const s = Math.sin(a);
-	if (axis === 'x') return [1, 0, 0, 0, 0, c, s, 0, 0, -s, c, 0, 0, 0, 0, 1];
-	if (axis === 'y') return [c, 0, -s, 0, 0, 1, 0, 0, s, 0, c, 0, 0, 0, 0, 1];
-	return [c, s, 0, 0, -s, c, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1];
-}
-
-/** Parse "xz" / "x-y" / "+y" into [{axis, side}] (side: -1 min, +1 max, 0 both). @param {string} spec */
-export function parseClamp(spec) {
-	const out = [];
-	let sign = 0;
-	for (const ch of spec || '') {
-		if (ch === '-') sign = -1;
-		else if (ch === '+') sign = 1;
-		else if (ch in AX) {
-			out.push({ axis: AX[/** @type {'x'|'y'|'z'} */ (ch)], side: sign });
-			sign = 0;
-		}
-	}
-	return out;
-}
-
-/**
- * Move every vertex within eps of a named bbox face onto it. Returns how many moved.
- * @param {any} doc @param {string} spec @param {number} eps
- */
-export function seamClamp(doc, spec, eps = 0.04) {
-	const faces = parseClamp(spec);
-	if (!faces.length) return 0;
-	const scene = doc.getRoot().getDefaultScene() ?? doc.getRoot().listScenes()[0];
-	const b = getBounds(scene);
-	let moved = 0;
-	const seen = new Set();
-	for (const mesh of doc.getRoot().listMeshes()) {
-		for (const prim of mesh.listPrimitives()) {
-			const pos = prim.getAttribute('POSITION');
-			if (!pos || seen.has(pos)) continue;
-			seen.add(pos);
-			const v = [0, 0, 0];
-			for (let i = 0; i < pos.getCount(); i++) {
-				pos.getElement(i, v);
-				let changed = false;
-				for (const { axis, side } of faces) {
-					if (side <= 0 && v[axis] - b.min[axis] < eps && v[axis] !== b.min[axis]) {
-						v[axis] = b.min[axis];
-						changed = true;
-					}
-					if (side >= 0 && b.max[axis] - v[axis] < eps && v[axis] !== b.max[axis]) {
-						v[axis] = b.max[axis];
-						changed = true;
-					}
-				}
-				if (changed) {
-					pos.setElement(i, v);
-					moved++;
-				}
-			}
-		}
-	}
-	return moved;
-}
-
-/**
- * Sci-fi pieces carry their own lights (a door's light stripes, a pad's rings, a screen):
- * Meshy paints them into the albedo as bright teal but ships no usable emissive map. The
- * mask keeps every albedo pixel whose hue is in [lo, hi]° with saturation ≥ sat and value
- * ≥ val (0-1), black elsewhere, and becomes the emissive texture — so exactly the painted
- * lights glow, never the teal PAINT (darker) or the white panels (unsaturated).
- * Returns the fraction of pixels lit (in %), 0 when the material has no albedo.
- * @param {any} doc @param {any} mat @param {{hue: number[], sat?: number, val?: number, strength?: number}} o
- */
-export async function glowMask(doc, mat, o) {
-	const tex = mat.getBaseColorTexture();
-	if (!tex) return 0;
-	const { data, info } = await sharp(Buffer.from(tex.getImage())).removeAlpha().raw().toBuffer({ resolveWithObject: true });
-	const out = Buffer.alloc(data.length);
-	let lit = 0;
-	for (let i = 0; i < data.length; i += 3) {
-		const r = data[i] / 255;
-		const g = data[i + 1] / 255;
-		const b = data[i + 2] / 255;
-		const max = Math.max(r, g, b);
-		const d = max - Math.min(r, g, b);
-		const h = d === 0 ? 0 : max === r ? (60 * ((g - b) / d) + 360) % 360 : max === g ? 60 * ((b - r) / d) + 120 : 60 * ((r - g) / d) + 240;
-		if (max >= (o.val ?? 0.55) && d / (max || 1) >= (o.sat ?? 0.35) && h >= o.hue[0] && h <= o.hue[1]) {
-			out[i] = data[i];
-			out[i + 1] = data[i + 1];
-			out[i + 2] = data[i + 2];
-			lit++;
-		}
-	}
-	const img = await sharp(out, { raw: { width: info.width, height: info.height, channels: 3 } }).jpeg({ quality: 88 }).toBuffer();
-	const em = doc.createTexture(`${mat.getName() || 'mat'}_glow`).setImage(new Uint8Array(img)).setMimeType('image/jpeg');
-	mat.setEmissiveTexture(em).setEmissiveFactor([1, 1, 1]);
-	if (o.strength && o.strength !== 1) {
-		const ext = doc.createExtension(KHRMaterialsEmissiveStrength);
-		mat.setExtension('KHR_materials_emissive_strength', ext.createEmissiveStrength().setEmissiveStrength(o.strength));
-	}
-	return +((100 * lit) / (info.width * info.height)).toFixed(2);
-}
-
-/** rgb (0-1) → [h°, s, v] */
-export function hsv(r, g, b) {
-	const max = Math.max(r, g, b);
-	const d = max - Math.min(r, g, b);
-	const h = d === 0 ? 0 : max === r ? (60 * ((g - b) / d) + 360) % 360 : max === g ? 60 * ((b - r) / d) + 120 : 60 * ((r - g) / d) + 240;
-	return [h, max ? d / max : 0, max];
-}
-
-/**
- * A hue-selective grade of the albedo: pixels whose hue is in [lo, hi]° (and saturation
- * ≥ 0.12, so greys are left alone) get their saturation × sat, value × val and hue + shift° — e.g. the
- * wall's all-teal frame → warm gunmetal, keeping its painted shading. Returns % of pixels.
- * @param {any} mat @param {{hue: number[], sat?: number, val?: number, shift?: number}} o
- */
-export async function recolor(mat, o) {
-	const tex = mat.getBaseColorTexture();
-	if (!tex) return 0;
-	const { data, info } = await sharp(Buffer.from(tex.getImage())).removeAlpha().raw().toBuffer({ resolveWithObject: true });
-	let n = 0;
-	for (let i = 0; i < data.length; i += 3) {
-		const [h, s, v] = hsv(data[i] / 255, data[i + 1] / 255, data[i + 2] / 255);
-		if (s < 0.12 || h < o.hue[0] || h > o.hue[1]) continue;
-		const s2 = Math.min(1, s * (o.sat ?? 1));
-		const v2 = Math.min(1, v * (o.val ?? 1));
-		// back to rgb: keep the pixel's own channel ratios' hue, re-spread for s2/v2
-		const h2 = (h + (o.shift ?? 0) + 360) % 360;
-		const c = v2 * s2;
-		const x = c * (1 - Math.abs(((h2 / 60) % 2) - 1));
-		const m = v2 - c;
-		const [r, g, b] = h2 < 60 ? [c, x, 0] : h2 < 120 ? [x, c, 0] : h2 < 180 ? [0, c, x] : h2 < 240 ? [0, x, c] : h2 < 300 ? [x, 0, c] : [c, 0, x];
-		data[i] = Math.round((r + m) * 255);
-		data[i + 1] = Math.round((g + m) * 255);
-		data[i + 2] = Math.round((b + m) * 255);
-		n++;
-	}
-	tex.setImage(new Uint8Array(await sharp(data, { raw: { width: info.width, height: info.height, channels: 3 } }).jpeg({ quality: 88 }).toBuffer())).setMimeType('image/jpeg');
-	return +((100 * n) / (info.width * info.height)).toFixed(2);
-}
-
-/**
- * @param {string} input @param {string} output @param {any} job
- */
-export async function kitPost(input, output, job) {
-	let src = input;
-	const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'kit-post-'));
-	try {
-		if (job.preRotate && Object.values(job.preRotate).some(Boolean)) {
-			const doc = await io.read(input);
-			for (const axis of /** @type {const} */ (['x', 'y', 'z'])) {
-				const deg = job.preRotate[axis];
-				if (!deg) continue;
-				// bake node transforms first would be meshy-post's job; Meshy raws are a
-				// single identity node, so rotating the mesh data is exact here
-				for (const mesh of doc.getRoot().listMeshes()) transformMesh(mesh, /** @type {any} */ (rot(axis, deg)));
-			}
-			src = path.join(tmp, 'rotated.glb');
-			await io.write(src, doc);
-		}
-		const mid = path.join(tmp, 'post.glb');
-		const report = await postProcess(src, mid, job);
-		const doc = await io.read(mid);
-		const moved = seamClamp(doc, job.clamp ?? '', job.eps ?? 0.04);
-		if (job.offset) {
-			// a piece that shares ANOTHER piece's pivot (a window sits 0.95 m up on the wall's
-			// bottom-centre origin, so both place at the same grid point and rotation)
-			const t = [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, job.offset[0] ?? 0, job.offset[1] ?? 0, job.offset[2] ?? 0, 1];
-			for (const mesh of doc.getRoot().listMeshes()) transformMesh(mesh, /** @type {any} */ (t));
-		}
-		let graded = 0;
-		for (const mat of doc.getRoot().listMaterials()) {
-			// a wall or a crate never glows: Meshy's refine sometimes ships a faint emissive map
-			// (a glowing floor is baked light in disguise) — drop it outright
-			if (job.dropEmissive !== false) mat.setEmissiveTexture(null).setEmissiveFactor([0, 0, 0]);
-			// a colour GRADE of the albedo, so every piece sits in one palette (Meshy read
-			// "oxblood" as cherry red and "slate" as lavender): sharp.modulate + JPEG
-			const tex = job.albedo && mat.getBaseColorTexture();
-			if (tex) {
-				const { saturation = 1, brightness = 1, hue = 0 } = job.albedo;
-				tex.setImage(new Uint8Array(await sharp(Buffer.from(tex.getImage())).modulate({ saturation, brightness, hue }).jpeg({ quality: 86 }).toBuffer()));
-				tex.setMimeType('image/jpeg');
-				graded++;
-			}
-		}
-		let recolored = 0;
-		if (job.recolor) for (const mat of doc.getRoot().listMaterials()) recolored += await recolor(mat, job.recolor);
-		let glowing = 0;
-		if (job.glow) for (const mat of doc.getRoot().listMaterials()) glowing += await glowMask(doc, mat, job.glow);
-		await doc.transform(prune());
-		await io.write(output, doc);
-		// the seam clamp folds relief within eps of a face INTO it: coplanar layers that
-		// z-fight while the camera moves (roadmap 33 K1, the Block). Settle them last.
-		const fight = await defightFile(output, output);
-		return { ...report, output, clamped: moved, defight: { pairs: fight.before, dropped: fight.dropped, pushed: fight.pushed }, graded, recolored, glowing, bytesOut: fs.statSync(output).size };
-	} finally {
-		fs.rmSync(tmp, { recursive: true, force: true });
-	}
-}
-
-if (process.argv[1] && import.meta.url === pathToFileURL(process.argv[1]).href) {
-	const [input, output, jobJson] = process.argv.slice(2);
-	if (!input || !output) {
-		console.error("usage: kit-post.mjs <raw.glb> <out.glb> '<job json>'");
-		process.exit(2);
-	}
-	const report = await kitPost(input, output, JSON.parse(jobJson || '{}'));
-	console.log(JSON.stringify(report));
-}
+// kit-post: the sci-fi kit's post step (glow mask, recolor included) now lives in
+// tools/kit-build/lib/post.mjs — roadmap 34 E2, one pack build tool instead of four forks. This file
+// stays so build.mjs and the tests keep their import.
+// CLI: node tools/kit-build/kit-build.mjs post <raw.glb> <out.glb> '<job json>'
+export { TOOLS, kitPost, parseClamp, seamClamp, glowMask, recolor, hsv } from '../kit-build/lib/post.mjs';
diff --git a/tools/town-kit/kit-post.mjs b/tools/town-kit/kit-post.mjs
index 126b3da..cb26cab 100644
--- a/tools/town-kit/kit-post.mjs
+++ b/tools/town-kit/kit-post.mjs
@@ -1,247 +1,9 @@
-// kit-post: the sci-fi kit's post step around tools/meshy's meshy-post.
-//
-//   raw Meshy GLB → pre-rotate (Meshy often lays a floor tile or roof slab upright, and
-//   meshy-post only turns about Y) → meshy-post (weld, simplify, stretch to the exact
-//   dims, pivot, 1024² JPEG) → SEAM CLAMP → pack GLB.
-//
-// The seam clamp is what makes pieces snap without gaps: Meshy's ends are never quite
-// planar (a stone sticks out 2 cm, the next one is 3 cm short), so after the stretch
-// every vertex within `eps` of a bbox face named in `clamp` is moved ONTO that face.
-// Two walls placed end to end then share one exact plane at their joint.
-//
-//   node kit-post.mjs <raw.glb> <out.glb> '<job json>'
-//   job = meshy-post's job + { preRotate?: {x?, y?, z?} degrees, clamp?: "x" | "xz" | "xyz" | "x-y" …,
-//         eps?: metres (default 0.04), offset?: [x, y, z] metres applied last,
-//         albedo?: {saturation, brightness, hue} grade of the base colour, dropEmissive?: false to keep it,
-//         glow?: {hue: [lo, hi], sat, val, strength} — light the albedo's own light strips (see glowMask),
-//         recolor?: {hue: [lo, hi], sat, val, shift} — scale saturation/value (and shift the hue) of that band only (see recolor) }
-// `clamp` lists axes; a trailing "-y" etc. means "the MIN face of y only" (a floor's bottom).
-import fs from 'node:fs';
-import os from 'node:os';
-import path from 'node:path';
-import { createRequire } from 'node:module';
-import { pathToFileURL } from 'node:url';
+// kit-post: the town kit's post step now lives in tools/kit-build/lib/post.mjs — roadmap 34 E2, one
+// pack build tool instead of four forks. This file stays so build.mjs and the tests keep their import.
+import { kitPost as post } from '../kit-build/lib/post.mjs';
 
-export const TOOLS = process.env.MESHY_TOOLS || path.resolve(path.dirname(new URL(import.meta.url).pathname), '../meshy');
-const req = createRequire(path.join(TOOLS, 'package.json'));
-const load = async (/** @type {string} */ id) => import(pathToFileURL(req.resolve(id)).href);
+export { TOOLS, parseClamp, seamClamp, glowMask, recolor, hsv } from '../kit-build/lib/post.mjs';
 
-const { NodeIO } = await load('@gltf-transform/core');
-const { ALL_EXTENSIONS, KHRMaterialsEmissiveStrength } = await load('@gltf-transform/extensions');
-const { getBounds, transformMesh, prune } = await load('@gltf-transform/functions');
-const { postProcess } = await import(pathToFileURL(path.join(TOOLS, 'lib/post.js')).href);
-const sharp = (await load('sharp')).default;
-
-const io = new NodeIO().registerExtensions(ALL_EXTENSIONS);
-const AX = { x: 0, y: 1, z: 2 };
-
-/** column-major 4x4 rotation about one axis @param {'x'|'y'|'z'} axis @param {number} deg */
-function rot(axis, deg) {
-	const a = (deg * Math.PI) / 180;
-	const c = Math.cos(a);
-	const s = Math.sin(a);
-	if (axis === 'x') return [1, 0, 0, 0, 0, c, s, 0, 0, -s, c, 0, 0, 0, 0, 1];
-	if (axis === 'y') return [c, 0, -s, 0, 0, 1, 0, 0, s, 0, c, 0, 0, 0, 0, 1];
-	return [c, s, 0, 0, -s, c, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1];
-}
-
-/** Parse "xz" / "x-y" / "+y" into [{axis, side}] (side: -1 min, +1 max, 0 both). @param {string} spec */
-export function parseClamp(spec) {
-	const out = [];
-	let sign = 0;
-	for (const ch of spec || '') {
-		if (ch === '-') sign = -1;
-		else if (ch === '+') sign = 1;
-		else if (ch in AX) {
-			out.push({ axis: AX[/** @type {'x'|'y'|'z'} */ (ch)], side: sign });
-			sign = 0;
-		}
-	}
-	return out;
-}
-
-/**
- * Move every vertex within eps of a named bbox face onto it. Returns how many moved.
- * @param {any} doc @param {string} spec @param {number} eps
- */
-export function seamClamp(doc, spec, eps = 0.04) {
-	const faces = parseClamp(spec);
-	if (!faces.length) return 0;
-	const scene = doc.getRoot().getDefaultScene() ?? doc.getRoot().listScenes()[0];
-	const b = getBounds(scene);
-	let moved = 0;
-	const seen = new Set();
-	for (const mesh of doc.getRoot().listMeshes()) {
-		for (const prim of mesh.listPrimitives()) {
-			const pos = prim.getAttribute('POSITION');
-			if (!pos || seen.has(pos)) continue;
-			seen.add(pos);
-			const v = [0, 0, 0];
-			for (let i = 0; i < pos.getCount(); i++) {
-				pos.getElement(i, v);
-				let changed = false;
-				for (const { axis, side } of faces) {
-					if (side <= 0 && v[axis] - b.min[axis] < eps && v[axis] !== b.min[axis]) {
-						v[axis] = b.min[axis];
-						changed = true;
-					}
-					if (side >= 0 && b.max[axis] - v[axis] < eps && v[axis] !== b.max[axis]) {
-						v[axis] = b.max[axis];
-						changed = true;
-					}
-				}
-				if (changed) {
-					pos.setElement(i, v);
-					moved++;
-				}
-			}
-		}
-	}
-	return moved;
-}
-
-/**
- * Sci-fi pieces carry their own lights (a door's light stripes, a pad's rings, a screen):
- * Meshy paints them into the albedo as bright teal but ships no usable emissive map. The
- * mask keeps every albedo pixel whose hue is in [lo, hi]° with saturation ≥ sat and value
- * ≥ val (0-1), black elsewhere, and becomes the emissive texture — so exactly the painted
- * lights glow, never the teal PAINT (darker) or the white panels (unsaturated).
- * Returns the fraction of pixels lit (in %), 0 when the material has no albedo.
- * @param {any} doc @param {any} mat @param {{hue: number[], sat?: number, val?: number, strength?: number}} o
- */
-export async function glowMask(doc, mat, o) {
-	const tex = mat.getBaseColorTexture();
-	if (!tex) return 0;
-	const { data, info } = await sharp(Buffer.from(tex.getImage())).removeAlpha().raw().toBuffer({ resolveWithObject: true });
-	const out = Buffer.alloc(data.length);
-	let lit = 0;
-	for (let i = 0; i < data.length; i += 3) {
-		const r = data[i] / 255;
-		const g = data[i + 1] / 255;
-		const b = data[i + 2] / 255;
-		const max = Math.max(r, g, b);
-		const d = max - Math.min(r, g, b);
-		const h = d === 0 ? 0 : max === r ? (60 * ((g - b) / d) + 360) % 360 : max === g ? 60 * ((b - r) / d) + 120 : 60 * ((r - g) / d) + 240;
-		if (max >= (o.val ?? 0.55) && d / (max || 1) >= (o.sat ?? 0.35) && h >= o.hue[0] && h <= o.hue[1]) {
-			out[i] = data[i];
-			out[i + 1] = data[i + 1];
-			out[i + 2] = data[i + 2];
-			lit++;
-		}
-	}
-	const img = await sharp(out, { raw: { width: info.width, height: info.height, channels: 3 } }).jpeg({ quality: 88 }).toBuffer();
-	const em = doc.createTexture(`${mat.getName() || 'mat'}_glow`).setImage(new Uint8Array(img)).setMimeType('image/jpeg');
-	mat.setEmissiveTexture(em).setEmissiveFactor([1, 1, 1]);
-	if (o.strength && o.strength !== 1) {
-		const ext = doc.createExtension(KHRMaterialsEmissiveStrength);
-		mat.setExtension('KHR_materials_emissive_strength', ext.createEmissiveStrength().setEmissiveStrength(o.strength));
-	}
-	return +((100 * lit) / (info.width * info.height)).toFixed(2);
-}
-
-/** rgb (0-1) → [h°, s, v] */
-export function hsv(r, g, b) {
-	const max = Math.max(r, g, b);
-	const d = max - Math.min(r, g, b);
-	const h = d === 0 ? 0 : max === r ? (60 * ((g - b) / d) + 360) % 360 : max === g ? 60 * ((b - r) / d) + 120 : 60 * ((r - g) / d) + 240;
-	return [h, max ? d / max : 0, max];
-}
-
-/**
- * A hue-selective grade of the albedo: pixels whose hue is in [lo, hi]° (and saturation
- * ≥ 0.12, so greys are left alone) get their saturation × sat, value × val and hue + shift° — e.g. the
- * wall's all-teal frame → warm gunmetal, keeping its painted shading. Returns % of pixels.
- * @param {any} mat @param {{hue: number[], sat?: number, val?: number, shift?: number}} o
- */
-export async function recolor(mat, o) {
-	const tex = mat.getBaseColorTexture();
-	if (!tex) return 0;
-	const { data, info } = await sharp(Buffer.from(tex.getImage())).removeAlpha().raw().toBuffer({ resolveWithObject: true });
-	let n = 0;
-	for (let i = 0; i < data.length; i += 3) {
-		const [h, s, v] = hsv(data[i] / 255, data[i + 1] / 255, data[i + 2] / 255);
-		// a band with lo > hi wraps through 0° (reds: [340, 15])
-		const inBand = o.hue[0] <= o.hue[1] ? h >= o.hue[0] && h <= o.hue[1] : h >= o.hue[0] || h <= o.hue[1];
-		if (s < (o.minSat ?? 0.12) || !inBand) continue;
-		const s2 = Math.min(1, s * (o.sat ?? 1));
-		const v2 = Math.min(1, v * (o.val ?? 1));
-		// back to rgb: keep the pixel's own channel ratios' hue, re-spread for s2/v2
-		const h2 = (h + (o.shift ?? 0) + 360) % 360;
-		const c = v2 * s2;
-		const x = c * (1 - Math.abs(((h2 / 60) % 2) - 1));
-		const m = v2 - c;
-		const [r, g, b] = h2 < 60 ? [c, x, 0] : h2 < 120 ? [x, c, 0] : h2 < 180 ? [0, c, x] : h2 < 240 ? [0, x, c] : h2 < 300 ? [x, 0, c] : [c, 0, x];
-		data[i] = Math.round((r + m) * 255);
-		data[i + 1] = Math.round((g + m) * 255);
-		data[i + 2] = Math.round((b + m) * 255);
-		n++;
-	}
-	tex.setImage(new Uint8Array(await sharp(data, { raw: { width: info.width, height: info.height, channels: 3 } }).jpeg({ quality: 88 }).toBuffer())).setMimeType('image/jpeg');
-	return +((100 * n) / (info.width * info.height)).toFixed(2);
-}
-
-/**
- * @param {string} input @param {string} output @param {any} job
- */
-export async function kitPost(input, output, job) {
-	let src = input;
-	const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'kit-post-'));
-	try {
-		if (job.preRotate && Object.values(job.preRotate).some(Boolean)) {
-			const doc = await io.read(input);
-			for (const axis of /** @type {const} */ (['x', 'y', 'z'])) {
-				const deg = job.preRotate[axis];
-				if (!deg) continue;
-				// bake node transforms first would be meshy-post's job; Meshy raws are a
-				// single identity node, so rotating the mesh data is exact here
-				for (const mesh of doc.getRoot().listMeshes()) transformMesh(mesh, /** @type {any} */ (rot(axis, deg)));
-			}
-			src = path.join(tmp, 'rotated.glb');
-			await io.write(src, doc);
-		}
-		const mid = path.join(tmp, 'post.glb');
-		const report = await postProcess(src, mid, job);
-		const doc = await io.read(mid);
-		const moved = seamClamp(doc, job.clamp ?? '', job.eps ?? 0.04);
-		if (job.offset) {
-			// a piece that shares ANOTHER piece's pivot (a window sits 0.95 m up on the wall's
-			// bottom-centre origin, so both place at the same grid point and rotation)
-			const t = [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, job.offset[0] ?? 0, job.offset[1] ?? 0, job.offset[2] ?? 0, 1];
-			for (const mesh of doc.getRoot().listMeshes()) transformMesh(mesh, /** @type {any} */ (t));
-		}
-		let graded = 0;
-		for (const mat of doc.getRoot().listMaterials()) {
-			// a wall or a crate never glows: Meshy's refine sometimes ships a faint emissive map
-			// (a glowing floor is baked light in disguise) — drop it outright
-			if (job.dropEmissive !== false) mat.setEmissiveTexture(null).setEmissiveFactor([0, 0, 0]);
-			// a colour GRADE of the albedo, so every piece sits in one palette (Meshy read
-			// "oxblood" as cherry red and "slate" as lavender): sharp.modulate + JPEG
-			const tex = job.albedo && mat.getBaseColorTexture();
-			if (tex) {
-				const { saturation = 1, brightness = 1, hue = 0 } = job.albedo;
-				tex.setImage(new Uint8Array(await sharp(Buffer.from(tex.getImage())).modulate({ saturation, brightness, hue }).jpeg({ quality: 86 }).toBuffer()));
-				tex.setMimeType('image/jpeg');
-				graded++;
-			}
-		}
-		let recolored = 0;
-		if (job.recolor) for (const mat of doc.getRoot().listMaterials()) recolored += await recolor(mat, job.recolor);
-		let glowing = 0;
-		if (job.glow) for (const mat of doc.getRoot().listMaterials()) glowing += await glowMask(doc, mat, job.glow);
-		await doc.transform(prune());
-		await io.write(output, doc);
-		return { ...report, output, clamped: moved, graded, recolored, glowing, bytesOut: fs.statSync(output).size };
-	} finally {
-		fs.rmSync(tmp, { recursive: true, force: true });
-	}
-}
-
-if (process.argv[1] && import.meta.url === pathToFileURL(process.argv[1]).href) {
-	const [input, output, jobJson] = process.argv.slice(2);
-	if (!input || !output) {
-		console.error("usage: kit-post.mjs <raw.glb> <out.glb> '<job json>'");
-		process.exit(2);
-	}
-	const report = await kitPost(input, output, JSON.parse(jobJson || '{}'));
-	console.log(JSON.stringify(report));
-}
+/** town-kit runs the z-fight pass itself, with a judge (build.mjs) — so not here
+ * @param {string} input @param {string} output @param {any} job */
+export const kitPost = (input, output, job) => post(input, output, { defight: false, ...job });