The waste fan x-offset was computed two ways: the renderer used
tableau_col_step * 0.224 while the hit-test hard-coded card_size.x * 0.28.
These coincide on desktop (col_step = 1.25*cw) but drift on Android, where
tighter column spacing (H_GAP_DIVISOR=32, col_step ~= 1.03*cw) makes the
renderer fan at ~0.231*cw. The top fanned waste card's sprite then sits
~14px left of its click target, so dragging the visible top card grabs
the card beneath it.
Extract waste_fan_step() and tableau_col_step() as the single source for
both the renderer (card_plugin::card_positions) and the hit-test
(input_plugin::card_position) so they can no longer diverge. Add a
regression test that simulates Android-tight spacing and asserts the hit
target tracks the renderer.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
funman300