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/hud_plugin/updates.rs

@@ -3,9 +3,9 @@
 use super::*;
 
 use bevy::window::WindowResized;
-use solitaire_core::{Foundation, KlondikePile, Tableau};
 use solitaire_core::Suit;
 use solitaire_core::{DrawStockConfig, game_state::GameMode};
+use solitaire_core::{Foundation, KlondikePile, Tableau};
 
 use crate::auto_complete_plugin::AutoCompleteState;
 
@@ -609,4 +609,3 @@ pub(super) fn resize_action_bar_labels(
         font.font_size = new_size;
     }
 }
-