feat(tile): render tiles with the mesh generator

Replace the per-shape tile geometries with @tts/mesh extrusion, honoring
the tile type and stretch aspect ratio. Add extrudeShapeParts so the
caps carry the texture while the walls are solid white, matching TTS
tinting. Fix bottom-face UVs to mirror horizontally and make wall UVs
inherit the front mapping independent of z.

pnpm-lock.yaml

@@ -66,6 +66,9 @@ importers:
       '@tts/extract':
         specifier: workspace:*
         version: link:../../packages/extract
+      '@tts/mesh':
+        specifier: workspace:*
+        version: link:../../packages/mesh
       '@tts/shared':
         specifier: workspace:*
         version: link:../../packages/shared