refactor: persist replay/save moves as KlondikeInstruction, not pile coords (#89)

Pile-position types (Tableau, Foundation, KlondikePile, KlondikePileStack)
are runtime-only and have no serde upstream. Per Rhys's guidance, the
persistence layer now stores the moves (KlondikeInstruction) rather than
board coordinates, decoding back to runtime pile positions on demand.

Core / data:
- game_state: instruction_history() -> Vec<KlondikeInstruction>; add
  instruction_to_piles() and apply_instruction(); drop AnyInstruction.
- klondike_adapter: delete the entire Saved* serde mirror section
  (SavedTableau/Foundation/SkipCards/KlondikePile/TableauStack/
  KlondikePileStack/DstFoundation/DstTableau/SavedInstruction).
- replay: drop the bespoke ReplayMove serde mirror; Replay.moves is now
  Vec<KlondikeInstruction>; REPLAY_SCHEMA_VERSION 2 -> 3.
- storage: game_state save format v3 rejected (v4/v5 only).

Engine / wasm consumers:
- record via KlondikeInstruction (stock click = RotateStock).
- playback decodes each instruction to (from, to, count) against the
  live state via instruction_to_piles, then fires the canonical event;
  undecodable instructions are skipped with a warning, never panic.
- remove all use solitaire_data::ReplayMove and Saved* imports.

Workspace check, clippy -D warnings, and the full test suite all pass.

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

solitaire_engine/src/replay_overlay/input.rs

@@ -8,6 +8,7 @@ use crate::replay_playback::{
     ReplayPlaybackState, step_backwards_replay_playback, step_replay_playback,
     stop_replay_playback, toggle_pause_replay_playback,
 };
+use crate::resources::GameStateResource;
 
 /// Per-arrow-key time-since-last-fire accumulators that drive the
 /// continuous-scrub repeat behaviour for held arrow keys. Each
@@ -1033,6 +1034,7 @@ pub(crate) fn handle_pause_button(
 /// guard lives inside `step_replay_playback`.
 pub(crate) fn handle_step_button(
     mut state: ResMut<ReplayPlaybackState>,
+    game: Option<Res<GameStateResource>>,
     mut moves_writer: MessageWriter<MoveRequestEvent>,
     mut draws_writer: MessageWriter<DrawRequestEvent>,
     buttons: Query<&Interaction, (With<ReplayStepButton>, Changed<Interaction>)>,
@@ -1040,7 +1042,12 @@ pub(crate) fn handle_step_button(
     if !buttons.iter().any(|i| *i == Interaction::Pressed) {
         return;
     }
-    step_replay_playback(&mut state, &mut moves_writer, &mut draws_writer);
+    step_replay_playback(
+        &mut state,
+        game.as_deref(),
+        &mut moves_writer,
+        &mut draws_writer,
+    );
 }
 
 /// Repaints the Pause / Resume button's label whenever
@@ -1112,6 +1119,7 @@ pub(crate) fn handle_pause_keyboard(
 pub(crate) fn handle_arrow_keyboard(
     keys: Option<Res<ButtonInput<KeyCode>>>,
     time: Res<Time>,
+    game: Option<Res<GameStateResource>>,
     mut hold: ResMut<ReplayScrubKeyHold>,
     mut state: ResMut<ReplayPlaybackState>,
     mut moves_writer: MessageWriter<MoveRequestEvent>,
@@ -1136,12 +1144,22 @@ pub(crate) fn handle_arrow_keyboard(
     // Right (forward step) — initial press fires immediately;
     // held repeats fire when the accumulator crosses the interval.
     if keys.just_pressed(KeyCode::ArrowRight) {
-        step_replay_playback(&mut state, &mut moves_writer, &mut draws_writer);
+        step_replay_playback(
+            &mut state,
+            game.as_deref(),
+            &mut moves_writer,
+            &mut draws_writer,
+        );
         hold.right_held_secs = 0.0;
     } else if keys.pressed(KeyCode::ArrowRight) {
         hold.right_held_secs += dt;
         if hold.right_held_secs >= SCRUB_REPEAT_INTERVAL_SECS {
-            step_replay_playback(&mut state, &mut moves_writer, &mut draws_writer);
+            step_replay_playback(
+                &mut state,
+                game.as_deref(),
+                &mut moves_writer,
+                &mut draws_writer,
+            );
             hold.right_held_secs = 0.0;
         }
     } else {