Replace 16×16 placeholder PNGs with 120×168 canvas-drawn art matching card
face dimensions. Each card back has a distinctive coloured pattern (blue diamond
grid, red crosshatch, green circle array, purple concentric diamonds, teal
horizontal stripes). Each background has textured detail (green felt weave, wood
plank grain, navy star field, burgundy diagonal tile, charcoal checkerboard).
Removes the now-unused save_small_png/make_small helpers.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
funman300
2b04718f33