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/replay_overlay/format.rs

@@ -246,7 +246,11 @@ pub(crate) fn format_suit_glyph(suit: Suit) -> &'static str {
 /// known card, or `"--"` for an absent top card (empty pile).
 pub(crate) fn format_card_short(card: Option<&(Card, bool)>) -> String {
     match card {
-        Some((c, _)) => format!("{}{}", format_rank_short(c.rank()), format_suit_glyph(c.suit())),
+        Some((c, _)) => format!(
+            "{}{}",
+            format_rank_short(c.rank()),
+            format_suit_glyph(c.suit())
+        ),
         None => "--".to_string(),
     }
 }