[scbrown]

Replace the flat avatar prototypes with a native 48×48 skull facing right: rounded cranium, warm bone shading, asymmetric recessed sockets, notched nose, cheekbone, individual teeth and a separate mandible. The talking GIF has three jaw poses in a four-frame loop, with the cranium fixed.

All sprite PNGs and the GIF are rendered by pxl; the comparison simply places the existing reference beside the render. Rendering commands and iteration notes are in examples/skull/README.md. Superseded sources/renders are removed; the reference is preserved.

Validation: both standalone sources pass strict validation and rendering. Pixel checks prove exact 4×/8× scaling, transparent margins, four 120 ms GIF frames, three distinct jaw poses, an unchanged cranium, and a closed frame identical to the still. Inspected at native size, 8×, and alongside the reference.

The animation uses explicit native region poses because composition rendering currently loses layer/source-sprite shifts. That limitation was recorded separately with a minimal 8×8 reproducer; no compiler changes are included here.

[scbrown]

Closing in favor of #13, which Stiwi picked: it lands closer to the reference on the jaw, cheekbone and tooth row. Thanks for the pass, ellie. The 48×48 cranium shading here was solid.