refactor(core): complete card_game::Card migration across engine + wasm

Finish the half-applied Card refactor. solitaire_core::card::Card is now an
alias for the opaque card_game::Card: suit()/rank() are methods, there is no
id or face_up field, and it is Clone+Eq+Hash but not Copy. Pile accessors
return Vec<(Card, bool)> where the bool is face-up.

Card identity is now the Card value itself (via Eq/Hash), not a numeric u32:
- CardEntity stores `card: Card` (was `card_id: u32`); lookups compare cards.
- Drag/selection collections and the touch/keyboard selection setters use
  Vec<Card>; CardFlippedEvent/CardFaceRevealedEvent/HintVisualEvent carry Card.
- replay_overlay and feedback/settle/deal animations updated accordingly.

solitaire_wasm: CardSnapshot derives its JSON id from suit+rank (matching the
desktop engine), and consumes the (Card, bool) pile tuples.

test-support: TestPileState tableau overrides now carry a per-card face-up flag
so tests can place face-down tableau cards. set_test_tableau_cards keeps its
Vec<Card> signature (defaulting to face-up); new set_test_tableau_cards_with_face
takes Vec<(Card, bool)>.

cargo test --workspace passes (engine lib 897 ok, 0 failed); cargo clippy
--workspace --all-targets -- -D warnings is clean. Save/serde format unchanged.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

solitaire_engine/src/cursor_plugin.rs

@@ -34,6 +34,7 @@
 
 use bevy::prelude::*;
 use bevy::window::{CursorIcon, PrimaryWindow, SystemCursorIcon};
+use solitaire_core::card::Card;
 use solitaire_core::{Foundation, KlondikePile, Tableau};
 use solitaire_core::{DrawMode, game_state::GameState};
 
@@ -185,7 +186,7 @@ fn cursor_over_draggable(cursor: Vec2, game: &GameState, layout: &Layout) -> boo
         let base = layout.pile_positions[&pile];
 
         for (i, card) in pile_cards.iter().enumerate().rev() {
-            if !card.face_up {
+            if !card.1 {
                 continue;
             }
             // Only the topmost card is draggable on non-tableau piles.
@@ -446,7 +447,7 @@ fn tableau_or_stack_pos(
     }
 }
 
-fn pile_cards(game: &GameState, pile: &KlondikePile) -> Vec<solitaire_core::card::Card> {
+fn pile_cards(game: &GameState, pile: &KlondikePile) -> Vec<(Card, bool)> {
     if matches!(pile, KlondikePile::Stock) {
         game.waste_cards()
     } else {
@@ -579,7 +580,7 @@ mod tests {
     // -----------------------------------------------------------------------
 
     use crate::layout::compute_layout;
-    use solitaire_core::card::{Card, Rank, Suit};
+    use solitaire_core::card::{Card, Deck, Rank, Suit};
     use solitaire_core::{DrawMode, game_state::{GameMode, GameState}};
 
     /// Builds an `App` with `MinimalPlugins` and the overlay system
@@ -618,7 +619,7 @@ mod tests {
             game.0.set_test_waste_cards(vec![dragged.clone()]);
         }
         let mut drag = app.world_mut().resource_mut::<DragState>();
-        drag.cards = vec![dragged.id];
+        drag.cards = vec![dragged];
         drag.origin_pile = Some(KlondikePile::Stock);
         drag.committed = true;
     }
@@ -632,19 +633,9 @@ mod tests {
         set_tableau_top(
             &mut game,
             2,
-            Card {
-                id: 9101,
-                suit: Suit::Clubs,
-                rank: Rank::Six,
-                face_up: true,
-            },
+            Card::new(Deck::Deck1, Suit::Clubs, Rank::Six),
         );
-        let dragged = Card {
-            id: 9102,
-            suit: Suit::Spades,
-            rank: Rank::Five,
-            face_up: true,
-        };
+        let dragged = Card::new(Deck::Deck1, Suit::Spades, Rank::Five);
 
         let mut app = overlay_test_app(game);
         begin_drag_with(&mut app, dragged);