fix(showcase): market-stall and watchtower visual quality pass (#179)

* fix(showcase): rebuild market stall with wrap plinths and a seated awning

Capped foot cubes and counter-leg pads z-fought at Z=0, and braces punched the counter. Wrap plates and a post-bay brace plane are durable; per-coordinate nudges are not.

Signed-off-by: TMHSDigital <154358121+TMHSDigital@users.noreply.github.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(showcase): rebuild watchtower with a closed shake roof and planted stiles

Incomplete courses left a wood U through the eave, and shoes lifted after the zmin snap. A solid cone plus post-snap collars are durable; per-coordinate nudges are not.

Signed-off-by: TMHSDigital <154358121+TMHSDigital@users.noreply.github.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

---------

Signed-off-by: TMHSDigital <154358121+TMHSDigital@users.noreply.github.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

Author: TMHSDigital

docs/gallery/assets/market-stall-hero.webp

@@ -936,7 +936,7 @@ <h2><a href="campfire/">campfire</a></h2>
         <div class="card-body">
           <h2><a href="market-stall/">market-stall</a></h2>
           <p class="teaches">A procedural timber market stall through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.</p>
-          <p class="witnesses"><span class="tag">witnesses</span> Recomputed: 4404 tris, three materials with 48 faces per awning stripe slot, UVs in 0..1 with zero AABB overlap, outer AABB 1.392×0.966×1.743 m, LOD ratios in band, convex collider 46 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.</p>
+          <p class="witnesses"><span class="tag">witnesses</span> Recomputed: 4324 tris, three materials with 34 faces per awning stripe slot, UVs in 0..1 with zero AABB overlap, outer AABB 1.389×1.011×1.740 m, grounded zmin, 4 wrap feet, brace-counter overlap 0, awning seat 4 mm, post plumb 0, LOD ratios in band, convex collider 58 tris, non-empty glTF. Hygiene all zero. --skip-decimate exits 9; --stray-vert 15; --lift-z/--short-feet 16; --low-brace 17; --float-awning 18; --rake-posts 19.</p>
           <a class="card-link" href="market-stall/">View example <span aria-hidden="true">&rarr;</span></a>
         </div>
       </article>
@@ -991,7 +991,7 @@ <h2><a href="fence-kit/">fence-kit</a></h2>
         <div class="card-body">
           <h2><a href="watchtower/">watchtower</a></h2>
           <p class="teaches">A procedural timber watchtower through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.</p>
-          <p class="witnesses"><span class="tag">witnesses</span> Recomputed: 5220 tris, three materials with 84 metal and 126 roof faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.434×1.434×1.982 m, LOD ratios in band, convex collider 56 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.</p>
+          <p class="witnesses"><span class="tag">witnesses</span> Recomputed: 6408 tris, three materials with 300 metal and 126 roof faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.594×1.594×2.973 m, grounded zmin, 4 iron shoes, rail engage 18 mm, collar standoff 2 mm, post plumb 0, LOD ratios in band (5.2 COLLAPSE leaner on LOD2), convex collider 150 tris, non-empty glTF. Hygiene all zero. --skip-decimate exits 9; --stray-vert 15; --lift-z/--short-shoes 16; --short-rails 17; --float-band 18; --rake-posts 19.</p>
           <a class="card-link" href="watchtower/">View example <span aria-hidden="true">&rarr;</span></a>
         </div>
       </article>

docs/gallery/assets/watchtower-hero.webp

@@ -57,7 +57,7 @@
       "name": "market-stall",
       "dir": "showcase/market-stall",
       "teaches": "A procedural timber market stall through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.",
-      "witnessesFix": "Recomputed: 4404 tris, three materials with 48 faces per awning stripe slot, UVs in 0..1 with zero AABB overlap, outer AABB 1.392×0.966×1.743 m, LOD ratios in band, convex collider 46 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.",
+      "witnessesFix": "Recomputed: 4324 tris, three materials with 34 faces per awning stripe slot, UVs in 0..1 with zero AABB overlap, outer AABB 1.389×1.011×1.740 m, grounded zmin, 4 wrap feet, brace-counter overlap 0, awning seat 4 mm, post plumb 0, LOD ratios in band, convex collider 58 tris, non-empty glTF. Hygiene all zero. --skip-decimate exits 9; --stray-vert 15; --lift-z/--short-feet 16; --low-brace 17; --float-awning 18; --rake-posts 19.",
       "hero": "docs/gallery/assets/market-stall-hero.webp",
       "preview": "showcase/market-stall/preview.webp",
       "tags": [
@@ -117,7 +117,7 @@
       "name": "watchtower",
       "dir": "showcase/watchtower",
       "teaches": "A procedural timber watchtower through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.",
-      "witnessesFix": "Recomputed: 5220 tris, three materials with 84 metal and 126 roof faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.434×1.434×1.982 m, LOD ratios in band, convex collider 56 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.",
+      "witnessesFix": "Recomputed: 6408 tris, three materials with 300 metal and 126 roof faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.594×1.594×2.973 m, grounded zmin, 4 iron shoes, rail engage 18 mm, collar standoff 2 mm, post plumb 0, LOD ratios in band (5.2 COLLAPSE leaner on LOD2), convex collider 150 tris, non-empty glTF. Hygiene all zero. --skip-decimate exits 9; --stray-vert 15; --lift-z/--short-shoes 16; --short-rails 17; --float-band 18; --rake-posts 19.",
       "hero": "docs/gallery/assets/watchtower-hero.webp",
       "preview": "showcase/watchtower/preview.webp",
       "tags": [

docs/gallery/index.html

@@ -1,10 +1,15 @@
 # Market stall
 
-A showcase piece, not an example. Procedural timber stall (posts with feet,
-slanted rafters, slatted counter and shelf, back-wall planks, eave fascia,
-striped awning and valance) then the shipped pipeline: unique-cell UVs,
-Cycles high-to-low normal bake, LOD chain, convex collider, Unity glTF
-export.
+A showcase piece, not an example. Procedural timber stall (corner posts
+with wrap plinths, slatted counter and shelf, back-wall planks, side
+braces that sit in the post bay, striped awning with a front roller and
+hanging valance) then the shipped pipeline: unique-cell UVs, Cycles
+high-to-low normal bake, LOD chain, convex collider, Unity glTF export.
+
+The old piece used capped foot cubes coplanar with the post bottoms and
+counter-leg pads coplanar with the legs, which z-fought at Z=0. Wrap
+plates stand off the post; counter legs go to Z=0 without a second
+bottom face.
 
 It asserts **budget conformance** of the generated result. It does not
 witness an API contract. "It rendered without error" is not a check.
@@ -22,38 +27,82 @@ materials, UVs, evaluated LOD, collider, or export file.
 
 | Axis | Declared | Measured (4.5.11 / 5.1.2 / 5.2.1) |
 | --- | --- | --- |
-| Base triangles | 4280–4550 | 4404 / 4404 / 4404 |
+| Base triangles | 3900–5200 | 4324 / 4324 / 4324 |
 | LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 |
-| LOD2 ratio | 0.10–0.35 of base | 0.2198 / 0.2198 / 0.2198 |
-| Materials | exactly 3 distinct, ≥16 faces per stripe slot | 3 slots, 48 / 48 stripe faces |
+| LOD2 ratio | 0.10–0.35 of base | 0.2197 / 0.2197 / 0.2197 |
+| Materials | exactly 3 distinct; ≥16 faces per stripe slot | 3 slots; 34 / 34 stripe faces |
 | UVs | in `0..1`, AABB overlap ≤ 1e-5 | in range, overlap 0 |
-| Outer AABB | (1.392, 0.966, 1.743) m ± 0.01 | (1.3915, 0.9659, 1.7430), zmin 0 |
-| Collider tris | ≤ 80 | 46 |
-| Export | written, size > 0 | 316748 / 316748 / 316724 bytes |
+| Outer AABB | (1.389, 1.011, 1.740) m ± 0.01 | (1.3892, 1.0107, 1.7402), zmin 0 |
+| Collider tris | ≤ 80 | 58 |
+| Export | written, size > 0 | 312752 / 312752 / 312728 bytes |
+
+### Hygiene
+
+Recomputed from the generated mesh, not asserted about the script.
 
-DECIMATE COLLAPSE triangle counts are **not** guaranteed identical across
-series — the gate is a ratio band, not an exact count. This mesh happened
-to match on 4.5.11 / 5.1.2 / 5.2.1. Bake pixels are stochastic; the gate
-is `has_data` plus operator `FINISHED`, not byte-identity. Construction
-uses no RNG. glTF byte size differs by a few bytes across series.
+| Axis | Declared | Measured (all three) |
+| --- | --- | --- |
+| Non-manifold edges | 0 | 0 |
+| Loose verts / edges | 0 / 0 | 0 / 0 |
+| Doubles merged at 1e-5 | 0 | 0 |
+| Zero-area faces | 0 | 0 |
+| N-gons | 0 | 0 |
+| Coplanar disjoint face pairs | 0 | 0 |
+| Grounded: `zmin` | within 1e-4 of 0 | 0.0000 |
+| Named supports: 4 wrap feet | each `zmin` ≤ 1e-3 | 4, foot_z 0.00000 |
+| Frame plan | 1.36 × 0.92 m ± 0.04 | 1.3600 × 0.9200 |
+
+### Joint fit and seat
 
-`--skip-decimate` skips the LOD DECIMATE stage so LOD1 ratio is 1.0 and
-exit 9 fires. That is the named budget the falsifier violates.
+| Axis | Declared | Measured (all three) |
+| --- | --- | --- |
+| Brace-vs-counter overlap | ≤ 1e-6 m³ | 0.000000 |
+| Header-post tenon engage | ≥ 0.4 × tenon | 0.0595 |
+| Awning-on-header seat | −0.002–0.010 m | 0.00378 |
+| Post plumb (XY drift) | ≤ 0.008 m | 0.00000 |
+
+DECIMATE COLLAPSE triangle counts are **not** identical across series —
+the gate is a ratio band, not an exact count. Bake pixels are
+stochastic; the gate is `has_data` plus operator `FINISHED`, not
+byte-identity. Construction uses no RNG. Export byte counts differ by
+24 B on 5.2.1 (glTF serializer), not a gated axis.
+
+### Falsifiers
+
+Each violates one named budget. All eight were run on 4.5.11, 5.1.2 and
+5.2.1 and returned the same code on each.
+
+| Flag | Budget violated | Exit |
+| --- | --- | --- |
+| `--skip-decimate` | LOD1 ratio band | 9 |
+| `--stray-vert` | loose vertex count is 0 | 15 |
+| `--lift-z` | bounding box `zmin` is 0 | 16 |
+| `--short-feet` | named wrap-foot supports at Z=0 | 16 |
+| `--low-brace` | brace-vs-counter overlap | 17 |
+| `--float-awning` | awning-on-header seat | 18 |
+| `--rake-posts` | post plumb | 19 |
 
 ## Run
 
 ```bash
 blender --background --python market_stall.py --
 blender --background --python market_stall.py -- --skip-decimate
+blender --background --python market_stall.py -- --stray-vert
+blender --background --python market_stall.py -- --lift-z
+blender --background --python market_stall.py -- --short-feet
+blender --background --python market_stall.py -- --low-brace
+blender --background --python market_stall.py -- --float-awning
+blender --background --python market_stall.py -- --rake-posts
 blender --background --python market_stall.py -- --output stall.png
 ```
 
-Smoke does not pass `--output` or `--skip-decimate`.
+Smoke passes no flags.
 
 ## Exit codes
 
 File-local. `9` is a valid check code. `10` is reserved for
-`gallery_framing.check_framing` on the `--output` path.
+`gallery_framing.check_framing` on the `--output` path. `15`–`19` are the
+hygiene and joint-fit family.
 
 | Code | Meaning |
 | --- | --- |
@@ -72,3 +121,8 @@ File-local. `9` is a valid check code. `10` is reserved for
 | 12 | Bake did not finish or image has no data |
 | 13 | Export file missing or empty |
 | 14 | `--output` produced no file |
+| 15 | Mesh hygiene: loose, non-manifold, zero-area, doubles, n-gons, z-fight |
+| 16 | Not grounded: bounding box `zmin` off 0, or a named wrap foot floats |
+| 17 | Joint fit: brace occupying the counter volume |
+| 18 | Seat: awning-on-header gap |
+| 19 | Post plumb or frame plan off the stated real-world size |