feat(engine): surface upstream move-type counters and replay seek

Two unused-for-free upstream card_game/klondike features:

- GameState now exposes the granular KlondikeStats counters
  (move_to_foundation_count, move_to_tableau_count,
  move_from_foundation_count, flip_up_count) and the win modal shows a
  quiet per-move-type recap line built from them (e.g. "21 to
  foundation - 14 tableau moves - 9 flips")
- wasm ReplayPlayer gains seek(step): clamped jump to any position,
  rewinding via a stored copy of the recorded deal instead of reparsing
  the replay JSON; replay.js Prev now uses it

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -6,6 +6,23 @@ project follows [Semantic Versioning](https://semver.org/).
 
 ## [Unreleased]
 
+## [0.43.3] — 2026-07-10
+
+### Fixed
+
+- **Replays are now self-contained (schema v4).** A replay stores the dealt
+  board itself via the upstream `card_game` session serializers instead of
+  re-dealing from the seed at playback time, so replays survive RNG and
+  upstream upgrades that change the seed→deal mapping — the failure that had
+  silently broken every stored replay. The web player and web game now
+  exchange the full payload through the wasm layer (the old JS path hardcoded
+  `schema_version: 2`, uploaded empty move lists, and corrupted u64 seeds via
+  `Math.round`), and the replay viewer reports unplayable old-format replays
+  in the caption instead of dying silently. Pre-v4 replays are rejected by a
+  version gate; local histories repopulate with new wins. (#170)
+- **Difficulty-mode wins can upload.** The server's replay `mode` validation
+  now accepts data-carrying `GameMode` variants (previously a 400). (#170)
+
 ## [0.42.0] — 2026-07-06
 
 ### Added

solitaire_core/src/game_state.rs

@@ -461,6 +461,32 @@ impl GameState {
         self.session.stats().stats().recycle_count()
     }
 
+    /// Number of cards moved onto foundations this game, read from the
+    /// upstream session stats. Cumulative like [`Self::recycle_count`] —
+    /// not rolled back on undo.
+    pub fn move_to_foundation_count(&self) -> u32 {
+        self.session.stats().stats().move_to_foundation_count()
+    }
+
+    /// Number of stacks moved onto tableaus (from stock or another tableau)
+    /// this game, read from the upstream session stats. Cumulative — not
+    /// rolled back on undo.
+    pub fn move_to_tableau_count(&self) -> u32 {
+        self.session.stats().stats().move_to_tableau_count()
+    }
+
+    /// Number of cards taken back off a foundation this game, read from the
+    /// upstream session stats. Cumulative — not rolled back on undo.
+    pub fn move_from_foundation_count(&self) -> u32 {
+        self.session.stats().stats().move_from_foundation_count()
+    }
+
+    /// Number of face-down cards revealed (flipped up) this game, read from
+    /// the upstream session stats. Cumulative — not rolled back on undo.
+    pub fn flip_up_count(&self) -> u32 {
+        self.session.stats().stats().flip_up_bonus_count()
+    }
+
     /// Total moves made this game (draws, recycles, and card moves), derived
     /// from the session's instruction history length.
     pub fn move_count(&self) -> u32 {

solitaire_engine/src/win_summary_plugin.rs

@@ -18,7 +18,7 @@
 //! shake duration elapses.
 
 use bevy::prelude::*;
-use solitaire_core::game_state::GameMode;
+use solitaire_core::game_state::{GameMode, GameState};
 use solitaire_core::scoring::compute_time_bonus;
 use solitaire_data::AnimSpeed;
 
@@ -93,6 +93,40 @@ pub struct WinSummaryPending {
     /// score-breakdown reveal can format the mode-multiplier row
     /// (e.g. `Zen ×0.0`, `Classic ×1.0`).
     pub mode: GameMode,
+    /// Per-move-type recap of the winning game, e.g.
+    /// `"21 to foundation · 14 tableau moves · 9 flips · 1 recycle"`.
+    /// Built from the upstream session counters at win time; empty when
+    /// every counter is zero (synthesised test wins).
+    pub move_detail: String,
+}
+
+/// Formats the per-move-type recap line for the win modal from the
+/// upstream session counters. Zero-valued components are omitted so the
+/// line stays short; returns an empty string when nothing was counted
+/// (only possible for synthesised test wins).
+fn build_move_detail(game: &GameState) -> String {
+    let mut parts: Vec<String> = Vec::new();
+    let foundation = game.move_to_foundation_count();
+    if foundation > 0 {
+        parts.push(format!("{foundation} to foundation"));
+    }
+    let tableau = game.move_to_tableau_count();
+    if tableau > 0 {
+        parts.push(format!("{tableau} tableau moves"));
+    }
+    let flips = game.flip_up_count();
+    if flips > 0 {
+        parts.push(format!("{flips} flips"));
+    }
+    let recycles = game.recycle_count();
+    if recycles > 0 {
+        parts.push(format!("{recycles} recycles"));
+    }
+    let returns = game.move_from_foundation_count();
+    if returns > 0 {
+        parts.push(format!("{returns} foundation returns"));
+    }
+    parts.join(" \u{00B7} ")
 }
 
 /// Builds a human-readable XP breakdown string for the win modal.
@@ -492,6 +526,7 @@ fn cache_win_data(
         pending.challenge_level = challenge_level;
         pending.undo_count = game.0.undo_count();
         pending.mode = game.0.mode;
+        pending.move_detail = build_move_detail(&game.0);
 
         if is_new_record {
             toast.write(InfoToastEvent("New Record!".to_string()));
@@ -913,6 +948,18 @@ fn spawn_overlay(
                     ));
                 }
 
+                // Move-type recap (same quiet styling as the XP breakdown)
+                if !pending.move_detail.is_empty() {
+                    card.spawn((
+                        Text::new(pending.move_detail.clone()),
+                        TextFont {
+                            font_size: 15.0,
+                            ..default()
+                        },
+                        TextColor(TEXT_SECONDARY),
+                    ));
+                }
+
                 // Achievements unlocked this game — at most 3 shown explicitly;
                 // excess is summarised with "...and N more".
                 if !session.names.is_empty() {
@@ -1288,6 +1335,49 @@ mod tests {
         assert_eq!(p.mode, GameMode::Classic);
     }
 
+    #[test]
+    fn build_move_detail_fresh_game_is_empty() {
+        let game = GameState::new(42, solitaire_core::DrawStockConfig::DrawOne);
+        assert!(
+            build_move_detail(&game).is_empty(),
+            "no moves yet, so the recap line must be empty"
+        );
+    }
+
+    #[test]
+    fn build_move_detail_reports_played_move_types() {
+        use solitaire_core::KlondikeInstruction;
+        // Drive a real deal forward so the upstream counters accumulate:
+        // prefer foundation moves, then anything else, drawing as needed.
+        let mut game = GameState::new(42, solitaire_core::DrawStockConfig::DrawOne);
+        for _ in 0..80 {
+            let instructions = game.possible_instructions();
+            let next = instructions
+                .iter()
+                .copied()
+                .find(|i| matches!(i, KlondikeInstruction::DstFoundation(_)))
+                .or_else(|| instructions.into_iter().next());
+            match next {
+                Some(i) => {
+                    let _ = game.apply_instruction(i);
+                }
+                None => break,
+            }
+            if game.move_to_foundation_count() > 0 && game.move_to_tableau_count() > 0 {
+                break;
+            }
+        }
+        let detail = build_move_detail(&game);
+        assert!(
+            detail.contains("to foundation"),
+            "seed 42 reaches a foundation move within 80 plies; got: {detail}"
+        );
+        assert!(
+            !detail.contains("0 "),
+            "zero-valued components must be omitted; got: {detail}"
+        );
+    }
+
     #[test]
     fn build_xp_detail_slow_win_with_undo() {
         // 300s >= 120s → no speed bonus; undo used → no no-undo bonus.

solitaire_server/web/replay.js

@@ -315,10 +315,9 @@ btnPlay.addEventListener("click", () => {
     }, STEP_INTERVAL_MS);
 });
 
-/// Step the player back one move. Re-creates the ReplayPlayer and fast-
-/// forwards to (step_idx - 1) without rendering intermediate frames, then
-/// renders once so the CSS transition animates each card to its previous
-/// position.
+/// Step the player back one move via the wasm-side seek (rewinds to the
+/// recorded deal and fast-forwards internally), then renders once so the
+/// CSS transition animates each card to its previous position.
 function stepBack() {
     if (!player || player.step_idx() === 0) return;
     if (playInterval) {
@@ -326,12 +325,7 @@ function stepBack() {
         playInterval = null;
         btnPlay.textContent = "▶ Play";
     }
-    const target = player.step_idx() - 1;
-    player = new ReplayPlayer(replayJson);
-    for (let i = 0; i < target; i++) {
-        player.step();
-    }
-    render(player.state());
+    render(player.seek(player.step_idx() - 1));
     btnPrev.disabled = player.step_idx() === 0;
     btnRestart.disabled = player.step_idx() === 0;
     btnStep.disabled = false;

solitaire_wasm/src/lib.rs

@@ -110,6 +110,9 @@ impl From<&(Card, bool)> for CardSnapshot {
 #[wasm_bindgen]
 pub struct ReplayPlayer {
     game: GameState,
+    /// The recorded deal before any instruction, kept so [`Self::seek_native`]
+    /// can rewind without reparsing the replay JSON.
+    initial: GameState,
     moves: Vec<KlondikeInstruction>,
     step_idx: usize,
 }
@@ -144,12 +147,30 @@ impl ReplayPlayer {
         // the current build maps seeds to deals.
         let (game, moves) = GameState::from_recording(&replay.recording, replay.seed, replay.mode);
         Ok(Self {
+            initial: game.clone(),
             game,
             moves,
             step_idx: 0,
         })
     }
 
+    /// Jump to `step` (clamped to the move count): the board state after
+    /// `step` moves have been applied. Rewinds by resetting to the stored
+    /// initial deal, then fast-forwards — a few hundred instruction
+    /// applications, microseconds in practice.
+    pub fn seek_native(&mut self, step: usize) -> Result<StateSnapshot, MoveError> {
+        let target = step.min(self.moves.len());
+        if target < self.step_idx {
+            self.game = self.initial.clone();
+            self.step_idx = 0;
+        }
+        while self.step_idx < target {
+            self.game.apply_instruction(self.moves[self.step_idx])?;
+            self.step_idx += 1;
+        }
+        Ok(self.snapshot())
+    }
+
     /// Apply the next move. Returns `Ok(None)` once the list is exhausted.
     pub fn step_native(&mut self) -> Result<Option<StateSnapshot>, MoveError> {
         if self.step_idx >= self.moves.len() {
@@ -236,6 +257,25 @@ impl ReplayPlayer {
         }
     }
 
+    /// Jump directly to `step` moves applied (clamped to the move count)
+    /// and return the snapshot there. Backwards seeks rewind to the
+    /// recorded deal and fast-forward, so any position is O(replay length)
+    /// at worst — no JSON reparse, no intermediate renders.
+    ///
+    /// Throws `"replay_desync"` if a recorded move is illegal during the
+    /// fast-forward (corrupt recording).
+    pub fn seek(&mut self, step: usize) -> Result<JsValue, JsValue> {
+        match self.seek_native(step) {
+            Ok(snap) => {
+                serde_wasm_bindgen::to_value(&snap).map_err(|e| JsValue::from_str(&e.to_string()))
+            }
+            Err(e) => {
+                log_replay_move_error(&e);
+                Err(JsValue::from_str("replay_desync"))
+            }
+        }
+    }
+
     /// Total number of moves the replay contains.
     pub fn total_steps(&self) -> usize {
         self.moves.len()
@@ -1062,6 +1102,57 @@ mod tests {
         assert_eq!(orig["stock"], repl["stock"], "stock deal must match");
     }
 
+    /// `seek` must land on exactly the state produced by stepping — both
+    /// forwards (fast-forward from the current position) and backwards
+    /// (rewind to the recorded deal, then fast-forward).
+    #[test]
+    fn seek_matches_stepping_in_both_directions() {
+        let mut game = SolitaireGame {
+            game: GameState::new_with_mode(51, DrawStockConfig::DrawOne, GameMode::Classic),
+        };
+        for _ in 0..24 {
+            let legal_moves = game.legal_moves_native();
+            if legal_moves.is_empty() {
+                break;
+            }
+            let idx = pick_move_index(&legal_moves).unwrap_or_default();
+            game.apply_legal_move_native(idx).expect("advance game");
+        }
+        let replay_json = game
+            .replay_export_native(60, "2026-07-10")
+            .expect("export replay");
+
+        let mut stepped = ReplayPlayer::from_json(&replay_json).expect("player A");
+        let mut seeker = ReplayPlayer::from_json(&replay_json).expect("player B");
+        let total = stepped.total_steps();
+        assert!(total >= 4, "test needs a few moves, got {total}");
+
+        // Forward: step A to k, seek B to k, compare snapshots.
+        let k = total / 2;
+        for _ in 0..k {
+            stepped.step_native().expect("step").expect("mid-replay");
+        }
+        let sought = seeker.seek_native(k).expect("seek forward");
+        assert_eq!(sought, stepped.snapshot(), "forward seek diverged at {k}");
+
+        // Backward: seek B to k - 2 and compare against a fresh stepper.
+        let back = k - 2;
+        let mut fresh = ReplayPlayer::from_json(&replay_json).expect("player C");
+        for _ in 0..back {
+            fresh.step_native().expect("step").expect("mid-replay");
+        }
+        let sought_back = seeker.seek_native(back).expect("seek backward");
+        assert_eq!(
+            sought_back,
+            fresh.snapshot(),
+            "backward seek diverged at {back}"
+        );
+
+        // Clamping: past-the-end seeks stop at the final state.
+        let end = seeker.seek_native(usize::MAX).expect("seek to end");
+        assert_eq!(end.step_idx, total);
+    }
+
     #[test]
     fn debug_api_autonomous_seed_batch_smoke() {
         for seed in 0_u64..128_u64 {