refactor: consolidate card_to_id into solitaire_core

Three byte-identical copies of the stable 0..=51 card-id helper
(suit_index*13 + rank-1) lived in feedback_anim_plugin, radial_menu, and
solitaire_wasm. The WASM copy's own comment notes it MUST match the engine
for cross-platform replay parity — exactly the kind of invariant a single
source of truth should enforce.

Add `solitaire_core::card::card_to_id(&Card) -> u32` and have all three
call sites import it. No behaviour change (same formula).

cargo test --workspace and cargo clippy --workspace --all-targets -- -D warnings pass.

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

solitaire_engine/src/feedback_anim_plugin.rs

@@ -188,19 +188,9 @@ pub fn deal_stagger_jitter(card_id: u32) -> f32 {
     (jitter_norm - 0.5) * 0.2 // ±0.1 == ±10 %
 }
 
-/// Converts a `Card` to a `u32` seed suitable for deterministic per-card
-/// jitter. Uses suit index × 13 + (rank value − 1) to produce a stable 0–51
-/// integer that survives changes to the internal `Card` representation.
-fn card_to_id(card: &Card) -> u32 {
-    use solitaire_core::card::Suit;
-    let suit_index = match card.suit() {
-        Suit::Clubs => 0,
-        Suit::Diamonds => 1,
-        Suit::Hearts => 2,
-        Suit::Spades => 3,
-    };
-    suit_index * 13 + (card.rank() as u32 - 1)
-}
+// Per-card jitter keys off the shared stable card id so it matches the
+// numeric identity used elsewhere (and on the WASM replay side).
+use solitaire_core::card::card_to_id;
 
 // ---------------------------------------------------------------------------
 // Plugin

solitaire_engine/src/radial_menu.rs

@@ -359,19 +359,7 @@ fn pile_cards(game: &GameState, pile: &KlondikePile) -> Vec<(Card, bool)> {
     }
 }
 
-/// Maps a `card_game::Card` to a stable `u32` identity used by `CardEntity`
-/// and systems that still track cards by numeric ID.
-/// Encoding: `suit_index * 13 + (rank as u8 - 1)`, range 0..=51.
-fn card_to_id(card: &Card) -> u32 {
-    use solitaire_core::card::Suit;
-    let suit_index: u32 = match card.suit() {
-        Suit::Clubs => 0,
-        Suit::Diamonds => 1,
-        Suit::Hearts => 2,
-        Suit::Spades => 3,
-    };
-    suit_index * 13 + (card.rank() as u32 - 1)
-}
+use solitaire_core::card::card_to_id;
 
 const fn foundations() -> [Foundation; 4] {
     [