MAX_DYNAMIC_FAN_FRAC 0.6 -> 0.9 so the dynamic tableau fill spreads
further on very tall / narrow viewports (e.g. a foldable cover screen),
which were left ~40% empty at the cap. Fills the unfolded near-square
screen to ~100% and lets the cover screen fill further (and the rest fills
as columns deepen during play). Normal phones are unaffected — their fill
fraction is already below the cap. apply_dynamic_tableau_fan still floors
at TABLEAU_FAN_FRAC and deeper columns drive the fraction down, so nothing
overflows and hit-testing stays in sync.
Vertical centring of the residual was investigated but dropped: a 21:9
phone is aspect-identical to the cover screen, so centring can't be
targeted to foldables without also disconnecting the board from the HUD on
tall phones.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>