test: cover mobile card label glyphs

CHANGELOG.md

@@ -55,6 +55,8 @@ project follows [Semantic Versioning](https://semver.org/).
 
 ### Tests
 
+- Added direct coverage for Android/touch card corner labels using Unicode suit
+  glyphs.
 - Added schema-v3 persistence round-trip coverage, foundation-to-tableau
   instruction coverage, expanded WASM unit tests, and Playwright E2E specs for
   browser routes and game-canvas behavior.

SESSION_HANDOFF.md

@@ -1,15 +1,15 @@
 # Ferrous Solitaire — Session Handoff
 
-**Last updated:** 2026-06-09 — analytics and Android validation runbooks added; handoff current.
+**Last updated:** 2026-06-09 — validation runbooks added; card label coverage tightened.
 
 ---
 
 ## Current state
 
-- **Branch state:** `master` pushed to origin; latest commits are validation runbooks plus handoff/changelog follow-up.
+- **Branch state:** `master` pushed to origin; latest commits are validation runbooks plus card-label test coverage.
 - **Latest tag:** `v0.39.0`
 - **Working tree:** clean. Local `scripts/` helpers are excluded through `.git/info/exclude` and intentionally not committed.
-- **Latest verification in this follow-up:** `cargo test -p solitaire_core`; `cargo test -p solitaire_data matomo_client`; `cargo test -p solitaire_engine analytics_plugin`; `cargo test -p solitaire_engine settings_plugin`.
+- **Latest verification in this follow-up:** `cargo test -p solitaire_core`; `cargo test -p solitaire_data matomo_client`; `cargo test -p solitaire_engine analytics_plugin`; `cargo test -p solitaire_engine settings_plugin`; `cargo test -p solitaire_engine card_plugin`.
 - **Full previous gate:** Claude reported recent card_game work pushed to origin and `cargo test` / `clippy` gates passing before the changelog follow-up.
 
 ---

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);