test: cover mobile card label glyphs

solitaire_engine/src/card_plugin.rs

@@ -3024,7 +3024,7 @@ mod tests {
     }
 
     // -----------------------------------------------------------------------
-    // label_for — remaining ranks not yet covered
+    // label_for / mobile_label_for
     // -----------------------------------------------------------------------
 
     #[test]
@@ -3081,6 +3081,26 @@ mod tests {
         }
     }
 
+    #[test]
+    fn mobile_label_for_uses_unicode_suit_glyphs() {
+        let cases = [
+            (Suit::Clubs, Rank::Two, "2♣"),
+            (Suit::Diamonds, Rank::Ten, "10♦"),
+            (Suit::Hearts, Rank::Queen, "Q♥"),
+            (Suit::Spades, Rank::Ace, "A♠"),
+        ];
+
+        for (suit, rank, expected) in cases {
+            let card = Card {
+                id: 0,
+                suit,
+                rank,
+                face_up: true,
+            };
+            assert_eq!(mobile_label_for(&card), expected);
+        }
+    }
+
     #[test]
     fn facedown_cards_use_tighter_fan_than_uniform_faceup_fan() {
         let g = GameState::new(42, solitaire_core::game_state::DrawMode::DrawOne);