style: cargo fmt under rustfmt 1.9 and gate formatting in CI

The repo was formatted under an older stable; rustfmt 1.9 (Rust 1.95)
wraps signatures and call sites differently, so every touched file was
picking up unrelated formatting hunks. One mechanical pass, and a
'cargo fmt --check' step in the test workflow (same pinned 1.95.0
toolchain) so drift can't accumulate again.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

solitaire_engine/src/cursor_plugin.rs

@@ -35,8 +35,8 @@
 use bevy::prelude::*;
 use bevy::window::{CursorIcon, PrimaryWindow, SystemCursorIcon};
 use solitaire_core::Card;
-use solitaire_core::{Foundation, KlondikePile, Tableau};
 use solitaire_core::{DrawStockConfig, game_state::GameState};
+use solitaire_core::{Foundation, KlondikePile, Tableau};
 
 use crate::card_plugin::RightClickHighlight;
 use crate::layout::{Layout, LayoutResource};
@@ -437,7 +437,8 @@ fn tableau_or_stack_pos(
             base.x,
             base.y - layout.card_size.y * layout.tableau_fan_frac * (index as f32),
         )
-    } else if matches!(pile, KlondikePile::Stock) && game.draw_mode() == DrawStockConfig::DrawThree {
+    } else if matches!(pile, KlondikePile::Stock) && game.draw_mode() == DrawStockConfig::DrawThree
+    {
         let pile_len = game.waste_cards().len();
         let visible_start = pile_len.saturating_sub(3);
         let slot = index.saturating_sub(visible_start) as f32;
@@ -581,7 +582,10 @@ mod tests {
 
     use crate::layout::compute_layout;
     use solitaire_core::{Card, Deck, Rank, Suit};
-    use solitaire_core::{DrawStockConfig, game_state::{GameMode, GameState}};
+    use solitaire_core::{
+        DrawStockConfig,
+        game_state::{GameMode, GameState},
+    };
 
     /// Builds an `App` with `MinimalPlugins` and the overlay system
     /// registered, plus the resources the system needs. Callers
@@ -630,11 +634,7 @@ mod tests {
         // — same colour family, illegal. Tableau(2) must NOT be
         // highlighted.
         let mut game = GameState::new_with_mode(7, DrawStockConfig::DrawOne, GameMode::Classic);
-        set_tableau_top(
-            &mut game,
-            2,
-            Card::new(Deck::Deck1, Suit::Clubs, Rank::Six),
-        );
+        set_tableau_top(&mut game, 2, Card::new(Deck::Deck1, Suit::Clubs, Rank::Six));
         let dragged = Card::new(Deck::Deck1, Suit::Spades, Rank::Five);
 
         let mut app = overlay_test_app(game);