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/card_plugin/mod.rs

@@ -14,8 +14,8 @@ use std::collections::HashMap;
 
 use bevy::color::Color;
 use bevy::prelude::*;
-use solitaire_core::{KlondikePile, Tableau};
 use solitaire_core::Card;
+use solitaire_core::{KlondikePile, Tableau};
 
 use crate::card_animation::CardAnimation;
 use crate::events::{CardFaceRevealedEvent, CardFlippedEvent};
@@ -577,10 +577,7 @@ impl Plugin for CardPlugin {
             // the chain each pair is a scheduler ambiguity (#143). All
             // members are cheap and mostly change-gated; sequential
             // execution is not a cost that matters here.
-            .configure_sets(
-                Update,
-                LayoutSystem::UpdateOnResize.before(BoardVisuals),
-            )
+            .configure_sets(Update, LayoutSystem::UpdateOnResize.before(BoardVisuals))
             .add_systems(
                 Update,
                 (
@@ -597,8 +594,7 @@ impl Plugin for CardPlugin {
                     clear_right_click_highlights_on_pause,
                     tick_hint_highlight,
                     update_stock_empty_indicator,
-                    update_stock_count_badge
-                        .run_if(resource_changed::<GameStateResource>),
+                    update_stock_count_badge.run_if(resource_changed::<GameStateResource>),
                     collect_resize_events,
                     snap_cards_on_window_resize,
                     resize_android_corner_labels,