beaded edge tray 3d model

3D printable model. Create a perfectly flat and planar rectangular tray base with rounded corners. The top surface must be completely smooth, level and uniform, no bumps, no curvature, no warping. Thickness consistent across the whole base. Around the entire perimeter, generate identical evenly spaced half-spheres (domes) forming a clean border. The domes should be perfectly symmetrical, touching each other, and aligned tangent to the base. Solid watertight mesh, no holes, no internal voids. Export as STL. Matte purple material for reference only