refactor: migrate PileType → KlondikePile across core/wasm/engine

- Replace PileType with typed KlondikePile (Foundation/Tableau variants)
  throughout solitaire_core, solitaire_wasm, and solitaire_engine;
  ReplayMove now uses SavedKlondikePile for serialisation stability
- Split replay_overlay.rs into replay_overlay/ module (mod, format,
  input, update, tests) for maintainability
- Add klondike dep to solitaire_engine and solitaire_data Cargo.toml
- Add TestPileState infrastructure to game_state.rs for engine unit tests
- Rebuild solitaire_wasm pkg (js + wasm artefacts updated)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

solitaire_server/web/pkg/solitaire_wasm.js

@@ -55,6 +55,8 @@ export class ReplayPlayer {
      * once the move list is exhausted.
      *
      * Returns `null` (not an exception) when the replay is finished.
+     * Throws `"replay_desync"` when the next recorded move is illegal for
+     * the current state, and logs the underlying core error to the JS console.
      * Throws a JS string exception on serialisation failure.
      * @returns {any}
      */
@@ -253,6 +255,9 @@ function __wbg_get_imports() {
         __wbg___wbindgen_throw_9c75d47bf9e7731e: function(arg0, arg1) {
             throw new Error(getStringFromWasm0(arg0, arg1));
         },
+        __wbg_error_48655ee7e4756f8b: function(arg0) {
+            console.error(arg0);
+        },
         __wbg_error_a6fa202b58aa1cd3: function(arg0, arg1) {
             let deferred0_0;
             let deferred0_1;