Items without an atlas entry were rendering as a hue-hashed coloured
square — bread/grain/vegetable hashed to pink-magenta, indistinguish-
able from a missing-texture placeholder.
Added _draw_item_shape() dispatcher with category-appropriate silhouettes
for: bread (brown loaf), grain (wheat stalks), vegetable (root with
leaves), flour (cream sack), meal (wooden bowl with steam), meat (red
steak with marbling), cloth (blue pleated bolt), medicine (white phial
with red cross), tool (hammer), weapon (sword), armor (helmet),
stone_block (pale brick), copper_ore (copper chunks), silver (silver
nuggets), ash (grey pile with smoke).
Hue-hashed fallback retained for safety but should be unreachable now
that every ALL_TYPES entry is handled by either _ITEM_SPRITES or
_draw_item_shape.