fix(engine): raise dynamic tableau fan cap to fill tall viewports

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>

CHANGELOG.md

@@ -41,7 +41,9 @@ project follows [Semantic Versioning](https://semver.org/).
   each column's total depth (face-down cards included) and refills on the
   cold-start deal, every move, and on resize (incl. the Android safe-area-inset
   resize and fold/unfold), so a near-square viewport such as an unfolded Galaxy
-  Fold no longer leaves the bottom of the screen empty.
+  Fold no longer leaves the bottom of the screen empty. The fan spread cap was
+  raised so very tall / narrow viewports (e.g. a foldable cover screen) fill
+  further.
 - **Card-move animation jank.** A move now rebuilds a card's child visuals only
   when its appearance changes (flip / resize / accessibility) instead of
   despawning and respawning every card's children each `StateChangedEvent`,