Replace compile-time include_bytes!() embedding for card faces, backgrounds,
and font with runtime AssetServer::load() calls. Swap in 52 xCards @2x PNGs
(LGPL-3.0) as card face assets and xCards bicycle_blue as back_0.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
funman300
