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/card_animation/interaction.rs

@@ -33,6 +33,7 @@ use std::collections::VecDeque;
 
 use bevy::prelude::*;
 use bevy::window::PrimaryWindow;
+use solitaire_core::card::Card;
 
 use super::animation::CardAnimation;
 use super::tuning::AnimationTuning;
@@ -210,12 +211,12 @@ pub(crate) fn apply_drag_visual(
 
     // Only lift cards that are in a *committed* drag. Pending drags (below
     // threshold) must stay at scale 1.0 to avoid visible premature lift.
-    let (dragged_ids, committed): (&[u32], bool) = drag
+    let (dragged_cards, committed): (&[Card], bool) = drag
         .as_ref()
         .map_or((&[], false), |d| (d.cards.as_slice(), d.committed));
 
     for (_, card, mut transform) in &mut cards {
-        let is_active_drag = committed && dragged_ids.contains(&card.card_id);
+        let is_active_drag = committed && dragged_cards.contains(&card.card);
         let target_scale = if is_active_drag { drag_scale } else { 1.0 };
         let current = transform.scale.x;
         let new_scale = current + (target_scale - current) * (DRAG_LERP_SPEED * dt).min(1.0);