fix(showcase): treasure-chest and tavern-stool visual quality pass (#175)

* fix(showcase): rebuild treasure-chest as a lofted vault with hinge knuckles

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

* fix(showcase): rebuild tavern-stool with lathed legs and ferrule cups

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

* docs(showcase): note spanning-board false gaps in joint-fit convention

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/tavern-stool-hero.webp

@@ -953,12 +953,12 @@ <h2><a href="street-lantern/">street-lantern</a></h2>
       </article>
       <article class="card" data-tags="mesh export showcase">
         <a class="card-media" href="treasure-chest/" aria-label="treasure-chest example detail page">
-          <img src="assets/treasure-chest-hero.webp" alt="treasure-chest — A procedural slatted treasure chest through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract." loading="lazy" decoding="async" />
+          <img src="assets/treasure-chest-hero.webp" alt="treasure-chest — A procedural iron-bound chest with a lofted barrel-vault lid, U-wrap bands, and hinge knuckles through UVs, bake, LOD, collider, and Unity glTF, asserting…" loading="lazy" decoding="async" />
         </a>
         <div class="card-body">
           <h2><a href="treasure-chest/">treasure-chest</a></h2>
-          <p class="teaches">A procedural slatted treasure chest 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: 5724 tris, two materials with 180 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.776×0.549×0.631 m, LOD ratios in band, convex collider 138 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.</p>
+          <p class="teaches">A procedural iron-bound chest with a lofted barrel-vault lid, U-wrap bands, and hinge knuckles 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: 3852 tris, two materials with 1608 wood and 318 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.764×0.542×0.691 m, LOD ratios in band, convex collider 176 tris, non-empty glTF. Hygiene all zero, four feet at zmin 0, lid-knuckle to hinge barrel 7 mm, band-wall gap 0. --float-hinge exits 17 on the hinge join; --narrow-bands exits 18 on the band seat.</p>
           <a class="card-link" href="treasure-chest/">View example <span aria-hidden="true">&rarr;</span></a>
         </div>
       </article>
@@ -1129,12 +1129,12 @@ <h2><a href="wall-torch/">wall-torch</a></h2>
       </article>
       <article class="card" data-tags="mesh export showcase">
         <a class="card-media" href="tavern-stool/" aria-label="tavern-stool example detail page">
-          <img src="assets/tavern-stool-hero.webp" alt="tavern-stool — A procedural tavern stool with a round seat, turned splayed legs, stretchers, and iron ferrules through UVs, bake, LOD, collider, and Unity glTF, asserting…" loading="lazy" decoding="async" />
+          <img src="assets/tavern-stool-hero.webp" alt="tavern-stool — A procedural tavern stool with a lathed seat, turned splayed legs, tenoned stretchers, and iron ferrule cups through UVs, bake, LOD, collider, and Unity glTF…" loading="lazy" decoding="async" />
         </a>
         <div class="card-body">
           <h2><a href="tavern-stool/">tavern-stool</a></h2>
-          <p class="teaches">A procedural tavern stool with a round seat, turned splayed legs, stretchers, and iron ferrules 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: 5396 tris, two materials with 2542 wood and 40 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.309×0.309×0.467 m, LOD ratios in band, convex collider 96 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.</p>
+          <p class="teaches">A procedural tavern stool with a lathed seat, turned splayed legs, tenoned stretchers, and iron ferrule cups 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: 2528 tris, two materials with 1168 wood and 256 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.340×0.340×0.470 m, LOD ratios in band, convex collider 396 tris, non-empty glTF. Hygiene all zero, four ferrule cups at zmin 0, stretcher-leg gap 0, ferrule clearance −1.25 mm. --float-stretchers exits 17 on the stretcher join; --pipe-ferrule exits 18 on the ferrule bite band.</p>
           <a class="card-link" href="tavern-stool/">View example <span aria-hidden="true">&rarr;</span></a>
         </div>
       </article>