Chocolate river tiles

Note: Real-world scale for a Candy Land ground piece: exactly 4.00 x 4.00 m footprint, 0.40 m thick at the frosting banks, 0.67 m to the top of the tallest gumdrop (GLB bounds x/z -2..2, y 0.000-0.672). Metres, +Y up, front faces +Z, origin at the tile centre on y = 0; the underside is one flat face at y = 0 and all four edges are vertical flat walls. The river runs along X on the centreline z = meander * sin(pi*x/2), so it enters and leaves at z = 0 with the same slope on both X edges, and the frosting ripple uses only 4 m-periodic frequencies, so opposite edges have identical profiles and the tile repeats seamlessly in every direction (along X the river continues; along Z bank meets bank). All decoration is inset from the edges so neighbouring tiles never collide. The exposed edge walls show a layer-cake cross-section (pink sponge, cream, chocolate sponge, mint frosting, with the river in section on the X edges); in a tiled layout these walls sit face to face and are hidden. Static model: no animation clip. 6862 triangles, 17 meshes, no textures; every surface is built from explicit triangles with baked face normals, so it stays flat-shaded in any engine. Material names are the Candy Land palette names verbatim (8 of the 12 are used); the design role is stored on material.userData.role. The exporter writes one material per mesh, so names repeat in the GLB (17 records, 8 distinct names); recolouring by name still catches all of them. flavourPalette sets the candy flavour mix: 0 makes every gumdrop lemon and every marshmallow warm white with lemon/white sprinkles, 1 makes them bubblegum pink / pink-light marshmallows with pink sprinkles, and values in between switch candies in a fixed spread order (default 0.5 is an even mix); the banks and river do not change. candyCount is an upper limit: gumdrops are only placed where they fit on the banks without touching the icing, so a wide or strongly meandering river fits fewer (for example 5 of 10 at riverWidth 2.0, meander 0.5). Part ids use the 'chocolateriver.' root because the kit's part-id grammar does not allow hyphens. All four params rebuild the model in the viewer; the downloadable GLB is the default build. Viewer staging overrides (lighting only, not in the GLB): exposure 0.4, sun key x0.75, hemisphere fill x2.2, environment reflections 0.4, chosen so the flat pastel faces render at their palette values instead of washing toward white. glb-lint reports 0 errors. Its overall verdict reads UNVERIFIED only because no requirements contract is supplied at this stage. Its 5 warnings are expected: material count and duplicate names (the per-mesh copies above), non-indexed primitives (intended flat shading), sibling bounding-box overlap (the river ribbon, swirls and stones sit inside the channel's bounds by design), and three 'detached' edge-wall bands (they share their boundary lines with the band below; only the bottom band reaches y = 0). The viewer's ground disc and lights are staging only and sit outside exportGLB({scope:'model'}).