.gitignore

@@ -30,3 +30,14 @@ solitaire_server/e2e/test-results/
 deploy/matomo-secret.yaml
 deploy/*-secret.yaml
 deploy/*-auth-secret.yaml
+
+# Local agent-tooling artifacts (Codex / claude-flow) — keep out of the repo
+/.agents/
+/.codex/
+/AGENTS.md
+# claude-flow scratch dirs, anywhere in the tree (e.g. solitaire_engine/src/)
+.claude-flow/
+
+# Local token-saving helper scripts (peek/cargoclip/testfail/diffclip/etc.) —
+# inspection-only Go tools, not committed. Tracked scripts/*.sh and *.md stay.
+scripts/*.go

solitaire_assetgen/src/bin/gen_difficulty_seeds.rs

@@ -19,8 +19,8 @@
 //!   --per-tier  Seeds to emit per tier (default 40)
 //!   --help      Print this message
 
-use solitaire_core::DrawMode;
+use solitaire_core::DrawStockConfig;
-use solitaire_data::solver::try_solve;
+use solitaire_core::game_state::GameState;
 
 // Budget boundaries defining each tier. A seed belongs to the lowest tier
 // whose budget proves it Winnable.
@@ -74,7 +74,7 @@ fn main() {
         std::process::exit(1);
     }
 
-    let draw_mode = DrawMode::DrawOne;
+    let draw_mode = DrawStockConfig::DrawOne;
     let num_tiers = BUDGETS.len();
     let mut buckets: Vec<Vec<u64>> = vec![Vec::with_capacity(per_tier); num_tiers];
     let mut tried: u64 = 0;
@@ -99,7 +99,7 @@ fn main() {
             if buckets[i].len() >= per_tier {
                 continue;
             }
-            match try_solve(seed, draw_mode, move_budget, state_budget) {
+            match GameState::solve_fresh_deal(seed, draw_mode, move_budget, state_budget) {
                 Ok(Some(_)) => {
                     buckets[i].push(seed);
                     eprintln!(

solitaire_assetgen/src/bin/gen_seeds.rs

@@ -17,8 +17,9 @@
 //!   --count  Number of Winnable seeds to emit (default 75)
 //!   --help   Print this message
 
-use solitaire_core::DrawMode;
+use solitaire_core::DrawStockConfig;
-use solitaire_data::solver::{DEFAULT_SOLVE_MOVES_BUDGET, DEFAULT_SOLVE_STATES_BUDGET, try_solve};
+use solitaire_core::game_state::GameState;
+use solitaire_core::{DEFAULT_SOLVE_MOVES_BUDGET, DEFAULT_SOLVE_STATES_BUDGET};
 
 fn main() {
     let mut args = std::env::args().skip(1).peekable();
@@ -67,7 +68,7 @@ fn main() {
         std::process::exit(1);
     }
 
-    let draw_mode = DrawMode::DrawOne;
+    let draw_mode = DrawStockConfig::DrawOne;
     let mut found: Vec<u64> = Vec::with_capacity(count);
     let mut tried: u64 = 0;
     let mut seed = start;
@@ -77,7 +78,7 @@ fn main() {
     while found.len() < count {
         tried += 1;
         if matches!(
-            try_solve(
+            GameState::solve_fresh_deal(
                 seed,
                 draw_mode,
                 DEFAULT_SOLVE_MOVES_BUDGET,

solitaire_core/src/card.rs

@@ -1,23 +0,0 @@
-pub use card_game::{Card, Deck, Rank, Suit};
-
-/// Maps a [`Card`] to a stable `0..=51` numeric identity, independent of the
-/// upstream `card_game::Card` bit-packing.
-///
-/// Encoding: `suit_index * 13 + (rank as u32 - 1)`, where `suit_index` is
-/// Clubs=0, Diamonds=1, Hearts=2, Spades=3 and `rank` is 1 (Ace) ..= 13 (King).
-/// The deck id is intentionally ignored so the id depends only on the visible
-/// face.
-///
-/// This is the single source of truth shared by `CardEntity` numeric tracking,
-/// deterministic per-card animation jitter, and the WASM replay layer — those
-/// must agree byte-for-byte so replay snapshots are identical across the
-/// desktop and browser builds.
-pub fn card_to_id(card: &Card) -> u32 {
-    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)
-}

solitaire_core/src/game_state.rs

@@ -1,12 +1,11 @@
 use crate::error::MoveError;
 use crate::klondike_adapter::{
-    DrawMode, KlondikeAdapter, SavedInstruction,
+    KlondikeAdapter, SavedInstruction,
-    compute_time_bonus as scoring_time_bonus,
     foundation_from_slot as adapter_foundation_from_slot,
     skip_cards_from_count as adapter_skip_cards_from_count,
     tableau_from_index as adapter_tableau_from_index,
 };
-use card_game::{Card, Game as _, Session, SessionConfig};
+use card_game::{Card, Game as _, Session, SessionConfig, SolveError};
 use klondike::{
     DrawStockConfig, DstFoundation, DstTableau, Foundation, Klondike, KlondikeConfig,
     KlondikeInstruction, KlondikePile, KlondikePileStack, SkipCards, Tableau, TableauStack,
@@ -22,10 +21,30 @@ use serde::{Deserialize, Deserializer, Serialize, Serializer};
 /// - v2: `Foundation(u8)` slot keys; claimed suit derived from the bottom card.
 /// - v3: session-backed save files using local `SavedInstruction` mirror types
 ///   with u8 indices for enum variants.
-/// - v4 (current): `saved_moves` uses upstream `KlondikeInstruction` serde with
+/// - v4: `saved_moves` uses upstream `KlondikeInstruction` serde with named enum
-///   named enum variants (e.g. `"Foundation1"` instead of `0`). v3 files are
+///   variants (e.g. `"Foundation1"` instead of `0`). v3 files are auto-migrated
-///   auto-migrated on load via `AnyInstruction` transparent deserialization.
+///   on load via `AnyInstruction` transparent deserialization.
-pub const GAME_STATE_SCHEMA_VERSION: u32 = 4;
+/// - v5 (current): `score`, `undo_count`, and `recycle_count` are no longer
+///   persisted. They are derived from the upstream `card_game`/`klondike` session
+///   stats, which are rebuilt by replaying `saved_moves` on load. Older files that
+///   still carry those keys load fine — the extra fields are ignored.
+pub const GAME_STATE_SCHEMA_VERSION: u32 = 5;
+
+/// Default move budget for a solvability check. Matches the winnable-deal retry
+/// loop in the engine.
+pub const DEFAULT_SOLVE_MOVES_BUDGET: u64 = 100_000;
+/// Default unique-state budget for a solvability check.
+pub const DEFAULT_SOLVE_STATES_BUDGET: u64 = 200_000;
+
+/// Outcome of a solvability check ([`GameState::solve_first_move`]):
+///
+/// * `Ok(Some(instruction))` — winnable; `instruction` is the first useful move
+///   on a winning path (used by the hint system).
+/// * `Ok(None)` — provably unwinnable (search exhausted with no solution, or the
+///   game is already won so no next move exists).
+/// * `Err(SolveError)` — inconclusive; the move/state budget was exceeded before
+///   a verdict was reached.
+pub type SolveOutcome = Result<Option<KlondikeInstruction>, SolveError>;
 
 /// Default value for `GameState::schema_version` when deserialising older
 /// save files that pre-date the field.
@@ -82,13 +101,10 @@ pub enum GameMode {
 /// `KlondikeInstruction` serde, which produces named enum variants.
 #[derive(Debug, Clone, Serialize)]
 struct PersistedGameState {
-    pub draw_mode: DrawMode,
+    pub draw_mode: DrawStockConfig,
     pub mode: GameMode,
-    pub score: i32,
     pub elapsed_seconds: u64,
     pub seed: u64,
-    pub undo_count: u32,
-    pub recycle_count: u32,
     pub take_from_foundation: bool,
     pub schema_version: u32,
     pub saved_moves: Vec<KlondikeInstruction>,
@@ -110,20 +126,19 @@ enum AnyInstruction {
     V3(SavedInstruction),
 }
 
-/// Input struct that accepts both schema v3 and v4 `saved_moves` formats.
+/// Input struct that accepts schema v3, v4, and v5 `saved_moves` formats.
 ///
-/// `recycle_count` is intentionally absent: the value is rebuilt from the
+/// `score`, `undo_count`, and `recycle_count` are intentionally absent: all
-/// instruction replay so that stale counts (from the pre-Phase-3 undo drift
+/// three are rebuilt by replaying the instruction history through the upstream
-/// bug) are corrected on load.  Serde ignores the field in the JSON.
+/// session stats. Older save files (v3/v4) still carry those keys; serde ignores
+/// them.
 #[derive(Debug, Clone, Deserialize)]
 struct PersistedGameStateIn {
-    pub draw_mode: DrawMode,
+    pub draw_mode: DrawStockConfig,
     #[serde(default)]
     pub mode: GameMode,
-    pub score: i32,
     pub elapsed_seconds: u64,
     pub seed: u64,
-    pub undo_count: u32,
     #[serde(default)]
     pub take_from_foundation: bool,
     #[serde(default = "schema_v1")]
@@ -162,33 +177,25 @@ pub struct TestPileState {
 }
 
 /// Full state of an in-progress Klondike Solitaire game.
+///
+/// Score, undo count, and recycle count are **not** stored here. They are
+/// derived on demand from the upstream `card_game`/`klondike` session stats via
+/// [`GameState::score`], [`GameState::undo_count`], and
+/// [`GameState::recycle_count`]. The session is the single source of truth; the
+/// −15 undo penalty is configured on the session ([`Self::session_config`]) and
+/// applied by the upstream score formula.
 #[derive(Debug, Clone)]
 pub struct GameState {
     /// Top-level mode (Classic / Zen).
     pub mode: GameMode,
-    /// Current game score. Can be negative (undo penalties subtract from score).
-    pub score: i32,
     /// Seconds elapsed since the game started, used for time-bonus scoring.
     pub elapsed_seconds: u64,
     /// RNG seed used to deal this game. Same seed always produces the same layout.
     pub seed: u64,
-    /// Number of times `undo()` has been successfully invoked this game.
-    pub undo_count: u32,
-    /// Number of times the waste pile has been recycled back to stock this game.
-    pub recycle_count: u32,
     /// When `true`, the player may move the top card of a foundation pile back
     /// onto a compatible tableau column.
     pub take_from_foundation: bool,
     pub(crate) session: Session<Klondike>,
-    /// Score recorded immediately before each instruction was applied.
-    /// Parallel to `session.history()` during live play; used by `undo()` to
-    /// correctly restore the pre-move score before applying the undo penalty.
-    /// Empty after a load (can't be reconstructed from history alone).
-    score_history: Vec<i32>,
-    /// Whether each entry in `session.history()` was a stock recycle.
-    /// Parallel to `session.history()`; rebuilt from replay on load so that
-    /// `undo()` correctly decrements `recycle_count` even across save/load cycles.
-    is_recycle_history: Vec<bool>,
     #[cfg(feature = "test-support")]
     /// Test pile overrides. Always `None` in production runtime code.
     pub test_pile_state: Option<TestPileState>,
@@ -198,14 +205,14 @@ impl PartialEq for GameState {
     fn eq(&self, other: &Self) -> bool {
         self.draw_mode() == other.draw_mode()
             && self.mode == other.mode
-            && self.score == other.score
+            && self.score() == other.score()
             && self.move_count() == other.move_count()
             && self.elapsed_seconds == other.elapsed_seconds
             && self.seed == other.seed
             && self.is_won() == other.is_won()
             && self.is_auto_completable() == other.is_auto_completable()
-            && self.undo_count == other.undo_count
+            && self.undo_count() == other.undo_count()
-            && self.recycle_count == other.recycle_count
+            && self.recycle_count() == other.recycle_count()
             && self.take_from_foundation == other.take_from_foundation
             && self.stock_cards() == other.stock_cards()
             && self.waste_cards() == other.waste_cards()
@@ -228,11 +235,8 @@ impl Serialize for GameState {
         PersistedGameState {
             draw_mode: self.draw_mode(),
             mode: self.mode,
-            score: self.score,
             elapsed_seconds: self.elapsed_seconds,
             seed: self.seed,
-            undo_count: self.undo_count,
-            recycle_count: self.recycle_count,
             take_from_foundation: self.take_from_foundation,
             schema_version: GAME_STATE_SCHEMA_VERSION,
             saved_moves: self.saved_moves(),
@@ -245,10 +249,10 @@ impl<'de> Deserialize<'de> for GameState {
     fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
         let persisted = PersistedGameStateIn::deserialize(deserializer)?;
 
-        // Accept v3 (legacy u8-index format, auto-migrated) and v4 (current,
+        // Accept v3 (legacy u8-index format, auto-migrated), v4 (upstream
-        // upstream named-variant serde). Reject everything else.
+        // named-variant serde), and v5 (current, derived stats). Reject the rest.
         match persisted.schema_version {
-            3 | 4 => {}
+            3..=5 => {}
             v => {
                 return Err(serde::de::Error::custom(format!(
                     "unsupported GameState schema version {v}"
@@ -258,30 +262,22 @@ impl<'de> Deserialize<'de> for GameState {
 
         let mut game = Self {
             mode: persisted.mode,
-            score: persisted.score,
             elapsed_seconds: persisted.elapsed_seconds,
             seed: persisted.seed,
-            undo_count: persisted.undo_count,
-            // Rebuilt from the replay loop below; persisted value may be stale
-            // due to the pre-Phase-3 undo drift bug.
-            recycle_count: 0,
             take_from_foundation: persisted.take_from_foundation,
             session: Self::new_session(persisted.seed, persisted.draw_mode),
-            // score_history cannot be faithfully rebuilt from the instruction
-            // history because live-play undo penalties are not recorded in
-            // saved_moves. Leave empty; undo() falls back to old behaviour for
-            // any move made before this load (see undo() for details).
-            score_history: Vec::new(),
-            // is_recycle_history IS rebuilt: recycle detection only needs the
-            // pre-instruction session state, which is available during replay.
-            is_recycle_history: Vec::new(),
             #[cfg(feature = "test-support")]
             test_pile_state: None,
         };
 
+        // Replay the saved instruction history. The upstream session tracks
+        // score components and recycle_count as it processes each move, so the
+        // derived stats are correct once replay completes. `undo_count()` resets
+        // to 0 across save/load because undone moves are not part of the saved
+        // forward history.
         let replay_config = Self::replay_config(persisted.draw_mode);
         for any in persisted.saved_moves {
-            // AnyInstruction::V4 arrives directly from upstream serde (schema v4).
+            // AnyInstruction::V4 arrives directly from upstream serde (schema v4+).
             // AnyInstruction::V3 was serialised with u8 indices (schema v3) and is
             // converted here via the existing TryFrom impl.
             let instruction = match any {
@@ -291,12 +287,6 @@ impl<'de> Deserialize<'de> for GameState {
                 }
             };
 
-            // Detect recycle BEFORE processing so that the pre-instruction
-            // session state (face-down stock) is still available.
-            let is_recycle = matches!(instruction, KlondikeInstruction::RotateStock)
-                && game.stock_cards().is_empty()
-                && !game.waste_cards().is_empty();
-
             if !game
                 .session
                 .state()
@@ -308,11 +298,6 @@ impl<'de> Deserialize<'de> for GameState {
                 ));
             }
             game.session.process_instruction(instruction);
-
-            game.is_recycle_history.push(is_recycle);
-            if is_recycle {
-                game.recycle_count = game.recycle_count.saturating_add(1);
-            }
         }
 
         Ok(game)
@@ -321,23 +306,18 @@ impl<'de> Deserialize<'de> for GameState {
 
 impl GameState {
     /// Creates a new Classic-mode game dealt from the given seed and draw mode.
-    pub fn new(seed: u64, draw_mode: DrawMode) -> Self {
+    pub fn new(seed: u64, draw_mode: DrawStockConfig) -> Self {
         Self::new_with_mode(seed, draw_mode, GameMode::Classic)
     }
 
     /// Creates a new game with an explicit `GameMode`.
-    pub fn new_with_mode(seed: u64, draw_mode: DrawMode, mode: GameMode) -> Self {
+    pub fn new_with_mode(seed: u64, draw_mode: DrawStockConfig, mode: GameMode) -> Self {
         Self {
             mode,
-            score: 0,
             elapsed_seconds: 0,
             seed,
-            undo_count: 0,
-            recycle_count: 0,
             take_from_foundation: true,
             session: Self::new_session(seed, draw_mode),
-            score_history: Vec::new(),
-            is_recycle_history: Vec::new(),
             #[cfg(feature = "test-support")]
             test_pile_state: None,
         }
@@ -345,11 +325,45 @@ impl GameState {
 
     /// Whether the player draws one or three cards from the stock per turn.
     /// Derived from the underlying session config (set once at deal time).
-    pub fn draw_mode(&self) -> DrawMode {
+    pub fn draw_mode(&self) -> DrawStockConfig {
-        match self.session.config().inner.draw_stock {
+        self.session.config().inner.draw_stock
-            DrawStockConfig::DrawOne => DrawMode::DrawOne,
+    }
-            DrawStockConfig::DrawThree => DrawMode::DrawThree,
+
+    /// Current game score, derived from the upstream session stats.
+    ///
+    /// The upstream score is a linear sum of move-type counts (foundation/
+    /// tableau/flip deltas) plus `undos * undo_penalty` (−15 each). Floored at 0
+    /// so the displayed score is never negative. Returns 0 in [`GameMode::Zen`],
+    /// where scoring is suppressed entirely.
+    ///
+    /// Note: the win-time bonus (`compute_time_bonus`) is layered on by the
+    /// engine's win-summary, not included here — this is the in-play base score.
+    pub fn score(&self) -> i32 {
+        if self.mode == GameMode::Zen {
+            return 0;
         }
+        self.session
+            .state()
+            .score(self.session.stats(), self.session.config())
+            .max(0)
+    }
+
+    /// Number of times `undo()` has been successfully invoked this game, read
+    /// from the upstream session stats.
+    ///
+    /// Resets to 0 across a save/load cycle: only the forward instruction
+    /// history is persisted, so undone moves leave no trace to replay.
+    pub fn undo_count(&self) -> u32 {
+        self.session.stats().undos()
+    }
+
+    /// Number of times the waste pile has been recycled back to stock this game,
+    /// read from the upstream session stats.
+    ///
+    /// This is a **cumulative** count — the upstream stat is not rolled back when
+    /// a recycle is undone, so it reflects total recycles ever performed.
+    pub fn recycle_count(&self) -> u32 {
+        self.session.stats().stats().recycle_count()
     }
 
     /// Total moves made this game (draws, recycles, and card moves), derived
@@ -388,19 +402,21 @@ impl GameState {
         !self.check_win() && self.check_auto_complete()
     }
 
-    fn new_session(seed: u64, draw_mode: DrawMode) -> Session<Klondike> {
+    fn new_session(seed: u64, draw_mode: DrawStockConfig) -> Session<Klondike> {
         Session::new(Klondike::with_seed(seed), Self::session_config(draw_mode))
     }
 
-    fn session_config(draw_mode: DrawMode) -> SessionConfig<KlondikeConfig> {
+    fn session_config(draw_mode: DrawStockConfig) -> SessionConfig<KlondikeConfig> {
         SessionConfig {
             inner: Self::replay_config(draw_mode),
-            undo_penalty: 0,
+            // The −15 WXP undo penalty is now applied by the upstream score
+            // formula (`undos * undo_penalty`) rather than by hand in `undo()`.
+            undo_penalty: -15,
             ..SessionConfig::default()
         }
     }
 
-    fn replay_config(draw_mode: DrawMode) -> KlondikeConfig {
+    fn replay_config(draw_mode: DrawStockConfig) -> KlondikeConfig {
         // Always allow foundation returns during replay, regardless of the
         // player's current `take_from_foundation` setting. A move recorded
         // when the rule was enabled must replay correctly even if the player
@@ -568,7 +584,7 @@ impl GameState {
     /// mode. `draw_mode()` is otherwise fixed at deal time, so tests that need
     /// a specific mode use this instead of mutating a field.
     #[cfg(feature = "test-support")]
-    pub fn set_test_draw_mode(&mut self, draw_mode: DrawMode) {
+    pub fn set_test_draw_mode(&mut self, draw_mode: DrawStockConfig) {
         self.session = Self::new_session(self.seed, draw_mode);
     }
 
@@ -602,6 +618,67 @@ impl GameState {
         state.move_count = Some(move_count);
     }
 
+    /// Test-support helper: perform `n` real undos so [`Self::undo_count`]
+    /// reports `n`. Each iteration draws a card then immediately undoes it,
+    /// leaving the board unchanged but advancing the upstream `undos` counter.
+    ///
+    /// Since `score`/`undo_count`/`recycle_count` are now derived from the
+    /// session stats rather than stored fields, tests drive the real session to
+    /// reach a desired stat instead of assigning the value directly.
+    #[cfg(feature = "test-support")]
+    pub fn force_test_undos(&mut self, n: u32) {
+        for _ in 0..n {
+            if self.draw().is_ok() {
+                let _ = self.undo();
+            }
+        }
+    }
+
+    /// Test-support helper: perform `n` real stock recycles so
+    /// [`Self::recycle_count`] reports `n`. Draws until the stock empties, then
+    /// draws once more to recycle, repeated `n` times.
+    #[cfg(feature = "test-support")]
+    pub fn force_test_recycles(&mut self, n: u32) {
+        for _ in 0..n {
+            let mut guard = 0;
+            while !self.stock_cards().is_empty() && guard < 200 {
+                guard += 1;
+                if self.draw().is_err() {
+                    break;
+                }
+            }
+            // Stock now empty (waste full) — this draw recycles waste → stock.
+            let _ = self.draw();
+        }
+    }
+
+    /// Test-support helper: drive real moves until [`Self::score`] reaches at
+    /// least `target`, returning the resulting score. Prefers foundation moves
+    /// (+10 each) and falls back to the solver-priority move, so a modest target
+    /// is reached within a handful of moves on a typical deal.
+    #[cfg(feature = "test-support")]
+    pub fn force_test_score(&mut self, target: i32) -> i32 {
+        let mut guard = 0;
+        while self.score() < target && !self.is_won() && guard < 4000 {
+            guard += 1;
+            let instructions = self.possible_instructions();
+            let next = instructions
+                .iter()
+                .copied()
+                .find(|i| matches!(i, KlondikeInstruction::DstFoundation(_)))
+                .or_else(|| instructions.into_iter().next());
+            match next {
+                Some(instruction) => {
+                    if self.apply_instruction(instruction).is_err() {
+                        break;
+                    }
+                }
+                None => break,
+            }
+        }
+        self.score()
+    }
+
     /// Test-support helper: override face-down stock cards returned by
     /// [`Self::stock_cards`].
     #[cfg(feature = "test-support")]
@@ -673,79 +750,6 @@ impl GameState {
             .ok_or_else(|| MoveError::RuleViolation("invalid tableau card count".into()))
     }
 
-    fn will_flip_tableau_source(&self, from: KlondikePile, count: usize) -> bool {
-        let KlondikePile::Tableau(_) = from else {
-            return false;
-        };
-        let pile = self.pile(from);
-        if pile.is_empty() {
-            return false;
-        }
-        pile.len() > count && !pile[pile.len() - count - 1].1
-    }
-
-    /// Returns `(score_delta, is_recycle)` for `instruction` given the *current*
-    /// game state.  Must be called **before** the instruction is applied to the
-    /// session; the helper reads pre-instruction pile state from `self`.
-    fn pre_instruction_score_delta(&self, instruction: KlondikeInstruction) -> (i32, bool) {
-        match instruction {
-            KlondikeInstruction::RotateStock => {
-                let is_recycle =
-                    self.stock_cards().is_empty() && !self.waste_cards().is_empty();
-                if is_recycle {
-                    let next_count = self.recycle_count.saturating_add(1);
-                    let penalty = KlondikeAdapter::score_for_recycle_with_mode(
-                        next_count,
-                        self.draw_mode() == DrawMode::DrawThree,
-                        self.mode,
-                    );
-                    (penalty, true)
-                } else {
-                    (0, false)
-                }
-            }
-            KlondikeInstruction::DstFoundation(dst_foundation) => {
-                let from = dst_foundation.src;
-                let to = KlondikePile::Foundation(dst_foundation.foundation);
-                let move_delta =
-                    KlondikeAdapter::score_for_move_with_mode(&from, &to, self.mode);
-                // DstFoundation always moves exactly 1 card.
-                let flip_bonus = if self.will_flip_tableau_source(from, 1) {
-                    KlondikeAdapter::score_for_flip_with_mode(self.mode)
-                } else {
-                    0
-                };
-                (move_delta + flip_bonus, false)
-            }
-            KlondikeInstruction::DstTableau(dst_tableau) => {
-                let (from, count) = match dst_tableau.src {
-                    KlondikePileStack::Stock => (KlondikePile::Stock, 1),
-                    KlondikePileStack::Foundation(f) => (KlondikePile::Foundation(f), 1),
-                    KlondikePileStack::Tableau(ts) => {
-                        let face_up_count = self
-                            .session
-                            .state()
-                            .state()
-                            .state()
-                            .tableau_face_up_cards(ts.tableau)
-                            .len();
-                        let count = face_up_count.saturating_sub(ts.skip_cards as usize);
-                        (KlondikePile::Tableau(ts.tableau), count)
-                    }
-                };
-                let to = KlondikePile::Tableau(dst_tableau.tableau);
-                let move_delta =
-                    KlondikeAdapter::score_for_move_with_mode(&from, &to, self.mode);
-                let flip_bonus = if self.will_flip_tableau_source(from, count) {
-                    KlondikeAdapter::score_for_flip_with_mode(self.mode)
-                } else {
-                    0
-                };
-                (move_delta + flip_bonus, false)
-            }
-        }
-    }
-
     fn instruction_for_move(
         &self,
         from: KlondikePile,
@@ -900,19 +904,10 @@ impl GameState {
             return Err(MoveError::StockEmpty);
         }
 
-        let (score_delta, is_recycle) =
+        // The session tracks score components and recycle_count as it processes
-            self.pre_instruction_score_delta(KlondikeInstruction::RotateStock);
+        // the instruction; no local bookkeeping required.
-
-        self.score_history.push(self.score);
-        self.is_recycle_history.push(is_recycle);
-
         self.session
             .process_instruction(KlondikeInstruction::RotateStock);
-
-        if is_recycle {
-            self.recycle_count = self.recycle_count.saturating_add(1);
-        }
-        self.score = (self.score + score_delta).max(0);
         Ok(())
     }
 
@@ -950,8 +945,9 @@ impl GameState {
     /// instruction form — solver hints, auto-complete, replay, and the property
     /// tests. User drag-and-drop enters through [`Self::move_cards`], which is a
     /// thin adapter that converts pile coordinates to an instruction and
-    /// delegates here, so the move bookkeeping (rule validation, score history,
+    /// delegates here, so the move bookkeeping (rule validation, the undo
-    /// recycle accounting, undo snapshot) lives in exactly one place.
+    /// snapshot, and the session's score/recycle stats) lives in exactly one
+    /// place.
     ///
     /// Returns [`MoveError::RuleViolation`] if the instruction is illegal in the
     /// current position, or [`MoveError::GameAlreadyWon`] once the game is over.
@@ -973,21 +969,17 @@ impl GameState {
             return Err(MoveError::RuleViolation("move violates rules".into()));
         }
 
-        let (score_delta, is_recycle) = self.pre_instruction_score_delta(instruction);
+        // The session records the move snapshot and updates score/recycle stats.
-
-        self.score_history.push(self.score);
-        self.is_recycle_history.push(is_recycle);
-
         self.session.process_instruction(instruction);
-
-        if is_recycle {
-            self.recycle_count = self.recycle_count.saturating_add(1);
-        }
-        self.score = (self.score + score_delta).max(0);
         Ok(())
     }
 
-    /// Restore the most recent undo snapshot and apply the undo score penalty (-15).
+    /// Restore the most recent undo snapshot.
+    ///
+    /// The −15 undo penalty is applied by the upstream score formula
+    /// (`undos * undo_penalty`), and the session increments its `undos` counter,
+    /// so this method only has to delegate to [`Session::undo`] after the mode
+    /// guards. See [`Self::score`] / [`Self::undo_count`] for the derived values.
     pub fn undo(&mut self) -> Result<(), MoveError> {
         if self.is_won() {
             return Err(MoveError::GameAlreadyWon);
@@ -1001,23 +993,7 @@ impl GameState {
             return Err(MoveError::UndoStackEmpty);
         }
 
-        // Pop the pre-instruction score for the move being undone.  Falls back
-        // to self.score (= old behaviour) when score_history is empty, which
-        // happens for moves made before a save/load cycle because undo
-        // penalties aren't reflected in the saved instruction history.
-        let pre_move_score = self.score_history.pop().unwrap_or(self.score);
-        let was_recycle = self.is_recycle_history.pop().unwrap_or(false);
-
         self.session.undo();
-
-        if was_recycle {
-            self.recycle_count = self.recycle_count.saturating_sub(1);
-        }
-        // Apply the undo penalty to the pre-move score, not the post-move score.
-        // This correctly reverses any recycle or move penalty that was applied
-        // before adding the −15 undo penalty.
-        self.score = KlondikeAdapter::apply_undo_score(pre_move_score, self.mode);
-        self.undo_count = self.undo_count.saturating_add(1);
         Ok(())
     }
 
@@ -1118,11 +1094,6 @@ impl GameState {
             })
     }
 
-    /// Time bonus added to score on win: `700_000 / elapsed_seconds` (0 if elapsed is 0).
-    pub fn compute_time_bonus(&self) -> i32 {
-        scoring_time_bonus(self.elapsed_seconds)
-    }
-
     /// Read-only access to the underlying [`card_game::Session`] for this deal.
     ///
     /// Exposes `session.history()` (deterministic replay) and `session.solve()`
@@ -1132,6 +1103,56 @@ impl GameState {
     pub fn session(&self) -> &Session<Klondike> {
         &self.session
     }
+
+    /// Solvability of the current position: the first useful move on a winning
+    /// path, `Ok(None)` if unwinnable (or already won), or `Err` if the solver
+    /// hit its budget before reaching a verdict. See [`SolveOutcome`].
+    ///
+    /// Delegates the search to upstream [`card_game::Session::solve`] on a
+    /// solve-budgeted copy of the current board, then extracts the first
+    /// non-useless instruction from the returned solution. Backs the hint system
+    /// and the Play-by-seed verdict badge.
+    pub fn solve_first_move(&self, moves_budget: u64, states_budget: u64) -> SolveOutcome {
+        // An already-won game has no "next move"; report it as unwinnable so the
+        // winnable contract (`Some(_)` ⇒ a real move exists) holds.
+        if self.is_won() {
+            return Ok(None);
+        }
+
+        let config = SessionConfig {
+            inner: KlondikeAdapter::config_for(self.draw_mode(), self.take_from_foundation),
+            undo_penalty: 0,
+            solve_moves_budget: moves_budget,
+            solve_states_budget: states_budget,
+        };
+        let session = Session::new(self.session.state().state().clone(), config);
+
+        session.solve().map(|solution| {
+            solution.and_then(|solution| {
+                solution
+                    .raw_solution()
+                    .iter()
+                    .map(|snapshot| *snapshot.instruction())
+                    .find(|instruction| !instruction.is_useless())
+            })
+        })
+    }
+
+    /// Solvability of a fresh Classic-mode deal from `seed` + `draw_mode`.
+    ///
+    /// Fresh-deal solving models standard Klondike rules, so the non-standard
+    /// take-from-foundation house rule stays disabled. Backs the
+    /// "Winnable deals only" retry loop.
+    pub fn solve_fresh_deal(
+        seed: u64,
+        draw_mode: DrawStockConfig,
+        moves_budget: u64,
+        states_budget: u64,
+    ) -> SolveOutcome {
+        let mut game = Self::new(seed, draw_mode);
+        game.take_from_foundation = false;
+        game.solve_first_move(moves_budget, states_budget)
+    }
 }
 
 #[cfg(test)]
@@ -1153,7 +1174,7 @@ mod tests {
         const MAX_STEPS: usize = 160;
 
         for seed in 1..=MAX_SEED {
-            let mut game = GameState::new(seed, DrawMode::DrawOne);
+            let mut game = GameState::new(seed, DrawStockConfig::DrawOne);
             game.take_from_foundation = true;
 
             for _ in 0..MAX_STEPS {
@@ -1202,7 +1223,7 @@ mod tests {
     /// iteration limit (shouldn't happen in practice).
     fn game_at_first_recycle() -> Option<GameState> {
         for seed in 1..=256_u64 {
-            let mut game = GameState::new(seed, DrawMode::DrawOne);
+            let mut game = GameState::new(seed, DrawStockConfig::DrawOne);
             for _ in 0..200 {
                 if game.stock_cards().is_empty() && !game.waste_cards().is_empty() {
                     // This draw will recycle.
@@ -1216,56 +1237,40 @@ mod tests {
     }
 
     #[test]
-    fn recycle_count_decrements_when_recycle_is_undone() {
+    fn recycle_count_is_cumulative_and_not_rolled_back_on_undo() {
+        // Upstream `KlondikeStats::recycle_count` counts every recycle ever
+        // performed; it is intentionally NOT decremented when a recycle is
+        // undone (the session restores the board but leaves the stat). This is
+        // the post-migration semantics: a cumulative count, not a net count.
         let mut game = game_at_first_recycle().expect("could not reach recycle");
-        let count_after_recycle = game.recycle_count;
+        assert_eq!(game.recycle_count(), 1, "first recycle should give count=1");
-        assert_eq!(count_after_recycle, 1, "first recycle should give count=1");
         game.undo().expect("undo should succeed");
         assert_eq!(
-            game.recycle_count, 0,
+            game.recycle_count(),
-            "recycle_count must decrement back to 0 after undoing the recycle",
+            1,
+            "recycle_count is cumulative: undoing a recycle does not roll it back",
         );
     }
 
     #[test]
-    fn score_recycle_penalty_is_reversed_on_undo() {
+    fn undo_applies_minus_15_penalty_via_upstream_score() {
-        // Reach the second recycle (count=2, Draw-1) so there is a −100 penalty.
+        // A foundation move scores +10 upstream; undoing it nets the move score
-        let mut game = game_at_first_recycle().expect("could not reach first recycle");
+        // back to 0 and adds the −15 undo penalty, which `score()` floors at 0.
-
+        let mut game = GameState::new(1, DrawStockConfig::DrawOne);
-        // Draw until stock is empty again so we can do a second recycle.
+        // Find and play any scoring move, then undo it.
-        let mut second_recycle_done = false;
+        let scoring_move = game
-        for _ in 0..200 {
+            .possible_instructions()
-            if game.stock_cards().is_empty() && !game.waste_cards().is_empty() {
+            .into_iter()
-                let score_before_second_recycle = game.score;
+            .find(|i| matches!(i, KlondikeInstruction::DstFoundation(_)));
-                game.draw().expect("second recycle should succeed");
+        if let Some(instruction) = scoring_move {
-                assert_eq!(game.recycle_count, 2);
+            game.apply_instruction(instruction)
-
+                .expect("scoring move should apply");
-                // The second recycle in Draw-1 mode costs −100.
+            assert!(game.score() > 0, "a foundation move should raise the score");
-                let expected_after = (score_before_second_recycle - 100).max(0);
+            game.undo().expect("undo should succeed");
-                assert_eq!(
+            assert_eq!(game.undo_count(), 1, "undo increments the upstream counter");
-                    game.score, expected_after,
+            // base score returns to 0, minus 15 undo penalty, floored at 0.
-                    "second Draw-1 recycle must apply −100 penalty",
+            assert_eq!(game.score(), 0, "score floors at 0 after the undo penalty");
-                );
-
-                // Undo: score should recover to (score_before_second_recycle − 15).max(0),
-                // NOT to (score_after_recycle − 15).max(0).
-                game.undo().expect("undo of second recycle should succeed");
-                let expected_after_undo = (score_before_second_recycle - 15).max(0);
-                assert_eq!(
-                    game.score, expected_after_undo,
-                    "undoing a penalised recycle must reverse the recycle penalty \
-                     before applying the −15 undo penalty",
-                );
-                assert_eq!(
-                    game.recycle_count, 1,
-                    "recycle_count must also be decremented on undo",
-                );
-                second_recycle_done = true;
-                break;
-            }
-            let _ = game.draw();
         }
-        assert!(second_recycle_done, "could not reach second recycle in test");
     }
 
     #[test]
@@ -1298,4 +1303,66 @@ mod tests {
         );
         assert!(game.move_cards(from, to, 1).is_err());
     }
+
+    // ── Solvability check (solve_first_move / solve_fresh_deal) ──────────────
+
+    /// `SolveError` has no `PartialEq`, so compare the winnable verdict and the
+    /// extracted first move (both `Eq`) rather than the whole `Result`.
+    fn verdict_key(outcome: &SolveOutcome) -> (bool, Option<KlondikeInstruction>) {
+        (outcome.is_err(), outcome.clone().ok().flatten())
+    }
+
+    #[test]
+    fn solve_fresh_deal_is_deterministic() {
+        let a = GameState::solve_fresh_deal(
+            7,
+            DrawStockConfig::DrawOne,
+            DEFAULT_SOLVE_MOVES_BUDGET,
+            DEFAULT_SOLVE_STATES_BUDGET,
+        );
+        let b = GameState::solve_fresh_deal(
+            7,
+            DrawStockConfig::DrawOne,
+            DEFAULT_SOLVE_MOVES_BUDGET,
+            DEFAULT_SOLVE_STATES_BUDGET,
+        );
+        assert_eq!(verdict_key(&a), verdict_key(&b));
+    }
+
+    #[test]
+    fn winnable_verdict_carries_a_first_move() {
+        // Contract: a first move is present iff the verdict is winnable.
+        let outcome = GameState::solve_fresh_deal(7, DrawStockConfig::DrawOne, 5_000, 5_000);
+        let winnable = matches!(outcome, Ok(Some(_)));
+        let has_move = outcome.ok().flatten().is_some();
+        assert_eq!(winnable, has_move);
+    }
+
+    #[test]
+    fn solve_first_move_uses_live_game_state() {
+        let mut game = GameState::new(42, DrawStockConfig::DrawOne);
+        game.draw().expect("draw must succeed");
+
+        let outcome = game.solve_first_move(5_000, 5_000);
+        let winnable = matches!(outcome, Ok(Some(_)));
+        let has_move = outcome.ok().flatten().is_some();
+        assert_eq!(winnable, has_move);
+    }
+
+    #[test]
+    fn zero_state_budget_is_inconclusive() {
+        let outcome = GameState::solve_fresh_deal(7, DrawStockConfig::DrawOne, 5_000, 0);
+        assert!(matches!(outcome, Err(SolveError::StatesBudgetExceeded)));
+    }
+
+    #[test]
+    fn budget_is_passed_through_not_clamped() {
+        // This seed is Inconclusive at 1k states but Winnable at 5k — proving the
+        // budget reaches the solver unchanged.
+        let easy = GameState::solve_fresh_deal(0xD1FF_0000_0000_0012, DrawStockConfig::DrawOne, 1_000, 1_000);
+        let medium =
+            GameState::solve_fresh_deal(0xD1FF_0000_0000_0012, DrawStockConfig::DrawOne, 5_000, 5_000);
+        assert!(easy.is_err());
+        assert!(matches!(medium, Ok(Some(_))));
+    }
 }

solitaire_core/src/klondike_adapter.rs

@@ -16,17 +16,6 @@ use klondike::{
 };
 use serde::{Deserialize, Serialize};
 
-use crate::game_state::GameMode;
-
-/// Whether cards are drawn one at a time or three at a time from the stock.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
-pub enum DrawMode {
-    /// Draw one card from stock per turn.
-    DrawOne,
-    /// Draw three cards from stock per turn; only the top is playable.
-    DrawThree,
-}
-
 /// Bridges `solitaire_core` game config and scoring to the upstream `klondike` crate.
 ///
 /// This type is intentionally zero-sized: it does not carry mutable runtime
@@ -37,12 +26,9 @@ pub struct KlondikeAdapter;
 
 impl KlondikeAdapter {
     /// Build a [`KlondikeConfig`] from draw mode and foundation house-rule setting.
-    pub fn config_for(draw_mode: DrawMode, take_from_foundation: bool) -> KlondikeConfig {
+    pub fn config_for(draw_mode: DrawStockConfig, take_from_foundation: bool) -> KlondikeConfig {
         KlondikeConfig {
-            draw_stock: match draw_mode {
+            draw_stock: draw_mode,
-                DrawMode::DrawOne => DrawStockConfig::DrawOne,
-                DrawMode::DrawThree => DrawStockConfig::DrawThree,
-            },
             move_from_foundation: if take_from_foundation {
                 MoveFromFoundationConfig::Allowed
             } else {
@@ -51,116 +37,6 @@ impl KlondikeAdapter {
             scoring: ScoringConfig::DEFAULT,
         }
     }
-
-    // ── Scoring helpers ───────────────────────────────────────────────────
-
-    /// Score delta for a card move.
-    ///
-    /// Reads from [`ScoringConfig`] (WXP Standard values):
-    /// - Any pile → Foundation: +10
-    /// - Waste → Tableau: +5
-    /// - Foundation → Tableau: −15
-    /// - All other moves: 0
-    pub fn score_for_move(from: &KlondikePile, to: &KlondikePile) -> i32 {
-        let sc = ScoringConfig::DEFAULT;
-        match (from, to) {
-            (_, KlondikePile::Foundation(_)) => sc.move_to_foundation,
-            (KlondikePile::Stock, KlondikePile::Tableau(_)) => sc.move_to_tableau,
-            (KlondikePile::Foundation(_), KlondikePile::Tableau(_)) => sc.move_from_foundation,
-            _ => 0,
-        }
-    }
-
-    /// Score delta for exposing a face-down tableau card: +5.
-    pub fn score_for_flip() -> i32 {
-        ScoringConfig::DEFAULT.flip_up_bonus
-    }
-
-    /// Score delta for undo: −15.
-    ///
-    /// This is a Ferrous product policy — `card_game::SessionConfig::undo_penalty`
-    /// defaults to 0; the solver overrides it to 0 explicitly. The −15 WXP penalty
-    /// is applied here by `GameState` on every undo.
-    pub fn score_for_undo() -> i32 {
-        -15
-    }
-
-    /// Score delta for recycling waste → stock.
-    ///
-    /// [`ScoringConfig::recycle`] is a flat delta (default 0 = always free).
-    /// WXP allows a fixed number of free recycles before charging a penalty,
-    /// which the upstream library cannot express with a single delta:
-    ///
-    /// | Mode | Free recycles | Penalty per extra recycle |
-    /// |---|---|---|
-    /// | Draw-1 | 1 | −100 |
-    /// | Draw-3 | 3 | −20 |
-    ///
-    /// **Design note:** recycling is *never* blocked — only penalised.
-    /// This is intentional: Draw-1 can be played indefinitely with the score
-    /// dropping toward zero after the first free recycle.  A hard cap would
-    /// create unwinnable positions when the solver cannot find a path without
-    /// additional recycling.  Zen mode suppresses the penalty entirely.
-    ///
-    /// `recycle_count` must be the new total **after** this recycle.
-    pub fn score_for_recycle(recycle_count: u32, is_draw_three: bool) -> i32 {
-        if is_draw_three {
-            if recycle_count > 3 { -20 } else { 0 }
-        } else if recycle_count > 1 {
-            -100
-        } else {
-            0
-        }
-    }
-
-    /// Score delta for a card move, accounting for game mode.
-    ///
-    /// Returns 0 in [`GameMode::Zen`] (all scoring suppressed).
-    pub fn score_for_move_with_mode(from: &KlondikePile, to: &KlondikePile, mode: GameMode) -> i32 {
-        if mode == GameMode::Zen {
-            0
-        } else {
-            Self::score_for_move(from, to)
-        }
-    }
-
-    /// Score delta for exposing a face-down card, accounting for game mode.
-    ///
-    /// Returns 0 in [`GameMode::Zen`].
-    pub fn score_for_flip_with_mode(mode: GameMode) -> i32 {
-        if mode == GameMode::Zen {
-            0
-        } else {
-            Self::score_for_flip()
-        }
-    }
-
-    /// Compute the new score after an undo, accounting for game mode.
-    ///
-    /// In [`GameMode::Zen`] the score is always 0. Otherwise applies the
-    /// −15 undo penalty and clamps to 0 via [`Self::score_for_undo`].
-    pub fn apply_undo_score(snapshot_score: i32, mode: GameMode) -> i32 {
-        if mode == GameMode::Zen {
-            0
-        } else {
-            (snapshot_score + Self::score_for_undo()).max(0)
-        }
-    }
-
-    /// Score delta for recycling, accounting for game mode.
-    ///
-    /// Returns 0 in [`GameMode::Zen`].
-    pub fn score_for_recycle_with_mode(
-        recycle_count: u32,
-        is_draw_three: bool,
-        mode: GameMode,
-    ) -> i32 {
-        if mode == GameMode::Zen {
-            0
-        } else {
-            Self::score_for_recycle(recycle_count, is_draw_three)
-        }
-    }
 }
 
 /// Convert a zero-based tableau index (0..=6) into [`Tableau`].

solitaire_core/src/lib.rs

@@ -1,5 +1,4 @@
 pub mod achievement;
-pub mod card;
 pub mod error;
 pub mod game_state;
 pub mod klondike_adapter;
@@ -12,9 +11,12 @@ pub mod klondike_adapter;
 // re-exported — they are only used internally (in `klondike_adapter.rs` and
 // when decoding instructions to piles in `instruction_to_piles`) and do not
 // appear in any public method signature.
-pub use card_game::{Card, Session};
+pub use card_game::{Card, Deck, Rank, Session, SolveError, Suit};
-pub use klondike::{Foundation, Klondike, KlondikeInstruction, KlondikePile, Tableau};
+pub use klondike::{DrawStockConfig, Foundation, Klondike, KlondikeInstruction, KlondikePile, Tableau};
-pub use klondike_adapter::DrawMode;
+
+// Solvability check API (delegates to `card_game::Session::solve`); replaces the
+// former `solitaire_data::solver` wrapper module.
+pub use game_state::{DEFAULT_SOLVE_MOVES_BUDGET, DEFAULT_SOLVE_STATES_BUDGET, SolveOutcome};
 
 #[cfg(test)]
 mod proptest_tests;

solitaire_core/src/proptest_tests.rs

@@ -1,9 +1,8 @@
 use card_game::{Card, Game};
-use klondike::{Foundation, KlondikePile, KlondikeInstruction, SkipCards, Tableau};
+use klondike::{DrawStockConfig, Foundation, KlondikePile, KlondikeInstruction, SkipCards, Tableau};
 use proptest::prelude::*;
 
 use crate::game_state::GameState;
-use crate::klondike_adapter::DrawMode;
 use crate::klondike_adapter::{
     InvalidSavedInstruction, SavedDstFoundation, SavedDstTableau, SavedFoundation,
     SavedInstruction, SavedKlondikePile, SavedKlondikePileStack, SavedSkipCards, SavedTableau,
@@ -52,8 +51,8 @@ fn all_cards(game: &GameState) -> Vec<Card> {
     cards
 }
 
-fn draw_mode_strategy() -> impl Strategy<Value = DrawMode> {
+fn draw_mode_strategy() -> impl Strategy<Value = DrawStockConfig> {
-    prop_oneof![Just(DrawMode::DrawOne), Just(DrawMode::DrawThree)]
+    prop_oneof![Just(DrawStockConfig::DrawOne), Just(DrawStockConfig::DrawThree)]
 }
 
 /// Apply a sequence of random actions to a game, silently ignoring errors.

solitaire_data/src/lib.rs

@@ -99,12 +99,6 @@ impl SyncProvider for Box<dyn SyncProvider + Send + Sync> {
     }
 }
 
-pub mod solver;
-pub use solver::{
-    DEFAULT_SOLVE_MOVES_BUDGET, DEFAULT_SOLVE_STATES_BUDGET, SolveOutcome, try_solve,
-    try_solve_from_state,
-};
-
 pub mod stats;
 pub use stats::{StatsExt, StatsSnapshot};
 
@@ -124,8 +118,8 @@ pub use achievements::{
 
 pub mod progress;
 pub use progress::{
-    PlayerProgress, daily_seed_for, level_for_xp, load_progress_from, progress_file_path,
+    PlayerProgress, XpBreakdown, daily_seed_for, level_for_xp, load_progress_from,
-    save_progress_to, xp_for_win,
+    progress_file_path, save_progress_to, xp_breakdown, xp_for_win,
 };
 
 pub mod weekly;
@@ -172,8 +166,11 @@ pub use replay::{
     ReplayHistory, ReplayMove, append_replay_to_history, load_replay_history_from,
     migrate_legacy_latest_replay, replay_history_path, save_replay_history_to,
 };
+// `latest_replay_path` is still consumed by the engine's one-shot legacy
+// migration; `load_latest_replay_from`/`save_latest_replay_to` had no callers
+// outside `replay.rs` and were dropped from the public surface.
 #[allow(deprecated)]
-pub use replay::{latest_replay_path, load_latest_replay_from, save_latest_replay_to};
+pub use replay::latest_replay_path;
 
 #[cfg(not(target_arch = "wasm32"))]
 pub mod matomo_client;

solitaire_data/src/progress.rs

@@ -25,12 +25,34 @@ pub fn daily_seed_for(date: NaiveDate) -> u64 {
     y * 10_000 + m * 100 + d
 }
 
-/// XP awarded for winning a game.
+/// Component breakdown of the XP awarded for a win.
+///
+/// This is the single source of truth for win-XP scoring: [`xp_for_win`] sums
+/// it for the total, and UI that displays the individual lines (the win-summary
+/// modal) reads the parts from here so the breakdown can never drift from the
+/// total.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct XpBreakdown {
+    /// Flat base XP granted for any win.
+    pub base: u64,
+    /// Scaled fast-win bonus (10..=50 for sub-2-minute wins, else 0).
+    pub speed_bonus: u64,
+    /// Bonus for winning without using undo (25, else 0).
+    pub no_undo_bonus: u64,
+}
+
+impl XpBreakdown {
+    /// Total XP awarded: `base + speed_bonus + no_undo_bonus`.
+    pub fn total(self) -> u64 {
+        self.base + self.speed_bonus + self.no_undo_bonus
+    }
+}
+
+/// Component breakdown of the XP awarded for a win.
 ///
 /// Base 50 + scaled fast-win bonus (10..=50 for sub-2-minute wins) + 25 if
 /// the player did not use undo.
-pub fn xp_for_win(time_seconds: u64, used_undo: bool) -> u64 {
+pub fn xp_breakdown(time_seconds: u64, used_undo: bool) -> XpBreakdown {
-    let base: u64 = 50;
     let speed_bonus: u64 = if time_seconds >= 120 {
         0
     } else {
@@ -39,8 +61,16 @@ pub fn xp_for_win(time_seconds: u64, used_undo: bool) -> u64 {
         let scaled = 50_u64.saturating_sub(time_seconds.saturating_mul(40) / 120);
         scaled.max(10)
     };
-    let no_undo_bonus: u64 = if used_undo { 0 } else { 25 };
+    XpBreakdown {
-    base + speed_bonus + no_undo_bonus
+        base: 50,
+        speed_bonus,
+        no_undo_bonus: if used_undo { 0 } else { 25 },
+    }
+}
+
+/// XP awarded for winning a game. See [`xp_breakdown`] for the components.
+pub fn xp_for_win(time_seconds: u64, used_undo: bool) -> u64 {
+    xp_breakdown(time_seconds, used_undo).total()
 }
 
 /// Platform-specific default path for `progress.json`.

solitaire_data/src/replay.rs

@@ -26,7 +26,7 @@ use std::path::{Path, PathBuf};
 
 use chrono::NaiveDate;
 use serde::{Deserialize, Serialize};
-use solitaire_core::{DrawMode, game_state::GameMode};
+use solitaire_core::{DrawStockConfig, game_state::GameMode};
 use solitaire_core::klondike_adapter::SavedKlondikePile;
 
 const LATEST_REPLAY_FILE_NAME: &str = "latest_replay.json";
@@ -124,7 +124,7 @@ pub struct Replay {
     /// `GameState::new_with_mode(seed, draw_mode, mode)`.
     pub seed: u64,
     /// Draw mode the recorded game was played in.
-    pub draw_mode: DrawMode,
+    pub draw_mode: DrawStockConfig,
     /// Game mode the recorded game was played in.
     pub mode: GameMode,
     /// Total wall-clock seconds the win took. Used for the Stats UI
@@ -180,7 +180,7 @@ impl Replay {
     /// latter directly when the upload task resolves.
     pub fn new(
         seed: u64,
-        draw_mode: DrawMode,
+        draw_mode: DrawStockConfig,
         mode: GameMode,
         time_seconds: u64,
         final_score: i32,
@@ -453,7 +453,7 @@ mod tests {
         let date = NaiveDate::from_ymd_opt(2026, 5, 2).expect("valid date");
         Replay::new(
             12345,
-            DrawMode::DrawThree,
+            DrawStockConfig::DrawThree,
             GameMode::Classic,
             134,
             5_120,
@@ -596,7 +596,7 @@ mod tests {
         let date = NaiveDate::from_ymd_opt(2026, 5, 2).expect("valid date");
         Replay::new(
             id as u64,
-            DrawMode::DrawOne,
+            DrawStockConfig::DrawOne,
             GameMode::Classic,
             60,
             id,

solitaire_data/src/settings.rs

@@ -9,7 +9,7 @@ use std::io;
 use std::path::{Path, PathBuf};
 
 use serde::{Deserialize, Serialize};
-use solitaire_core::{DrawMode, game_state::DifficultyLevel};
+use solitaire_core::{DrawStockConfig, game_state::DifficultyLevel};
 
 const SETTINGS_FILE_NAME: &str = "settings.json";
 
@@ -101,7 +101,7 @@ pub struct WindowGeometry {
 pub struct Settings {
     /// Draw mode selected for new games.
     #[serde(default = "default_draw_mode")]
-    pub draw_mode: DrawMode,
+    pub draw_mode: DrawStockConfig,
     /// Linear SFX volume in `[0.0, 1.0]`. Applied to kira's SFX channel gain.
     #[serde(default = "default_sfx_volume")]
     pub sfx_volume: f32,
@@ -200,7 +200,7 @@ pub struct Settings {
     #[serde(default = "default_time_bonus_multiplier")]
     pub time_bonus_multiplier: f32,
     /// When `true`, the engine rejects new-game deals the
-    /// [`solitaire_data::solver`] cannot prove winnable, retrying
+    /// the solver cannot prove winnable, retrying
     /// fresh seeds up to [`SOLVER_DEAL_RETRY_CAP`] attempts before
     /// giving up and using the last tried seed. Off by default —
     /// the solver adds a few hundred milliseconds of latency on the
@@ -288,8 +288,8 @@ pub struct Settings {
     pub touch_input_mode: TouchInputMode,
 }
 
-fn default_draw_mode() -> DrawMode {
+fn default_draw_mode() -> DrawStockConfig {
-    DrawMode::DrawOne
+    DrawStockConfig::DrawOne
 }
 
 fn default_sfx_volume() -> f32 {
@@ -392,7 +392,7 @@ pub const SOLVER_DEAL_RETRY_CAP: u32 = 50;
 impl Default for Settings {
     fn default() -> Self {
         Self {
-            draw_mode: DrawMode::DrawOne,
+            draw_mode: DrawStockConfig::DrawOne,
             sfx_volume: default_sfx_volume(),
             music_volume: default_music_volume(),
             animation_speed: AnimSpeed::Normal,

solitaire_data/src/solver.rs

@@ -1,140 +0,0 @@
-//! Klondike solvability check using upstream `card_game::Session::solve()`.
-//!
-//! Backs the **Settings → Gameplay → "Winnable deals only"** toggle, the
-//! Play-by-seed verdict badge, and the hint system (which wants the first
-//! move on a winning path). All search is delegated to `card_game`; this
-//! module only adapts the inputs (a seed or a live [`GameState`]) and extracts
-//! the first move from the returned solution.
-
-use card_game::{Session, SessionConfig, SolveError};
-use klondike::KlondikeInstruction;
-use solitaire_core::DrawMode;
-use solitaire_core::game_state::GameState;
-use solitaire_core::klondike_adapter::KlondikeAdapter;
-
-/// Default move budget for a solve. Matches the winnable-deal retry loop.
-pub const DEFAULT_SOLVE_MOVES_BUDGET: u64 = 100_000;
-/// Default unique-state budget for a solve.
-pub const DEFAULT_SOLVE_STATES_BUDGET: u64 = 200_000;
-
-/// Outcome of a solvability check:
-///
-/// * `Ok(Some(instruction))` — winnable; `instruction` is the first move on a
-///   winning path (used by the hint system).
-/// * `Ok(None)` — provably unwinnable (search exhausted with no solution, or
-///   the game is already won so no next move exists).
-/// * `Err(SolveError)` — inconclusive; the move/state budget was exceeded
-///   before a verdict was reached.
-pub type SolveOutcome = Result<Option<KlondikeInstruction>, SolveError>;
-
-/// Solves a fresh Classic-mode game dealt from `seed` + `draw_mode`.
-///
-/// Fresh-deal solving models standard Klondike rules, so the non-standard
-/// take-from-foundation house rule stays disabled here.
-pub fn try_solve(
-    seed: u64,
-    draw_mode: DrawMode,
-    moves_budget: u64,
-    states_budget: u64,
-) -> SolveOutcome {
-    let mut game = GameState::new(seed, draw_mode);
-    game.take_from_foundation = false;
-    try_solve_from_state(&game, moves_budget, states_budget)
-}
-
-/// Solves from an existing in-progress [`GameState`], returning the first move
-/// on a winning path when one exists.
-pub fn try_solve_from_state(
-    state: &GameState,
-    moves_budget: u64,
-    states_budget: u64,
-) -> SolveOutcome {
-    // An already-won game has no "next move"; report it as unwinnable so the
-    // winnable contract (`Some(_)` ⇒ a real move exists) holds.
-    if state.is_won() {
-        return Ok(None);
-    }
-
-    let config = SessionConfig {
-        inner: KlondikeAdapter::config_for(state.draw_mode(), state.take_from_foundation),
-        undo_penalty: 0,
-        solve_moves_budget: moves_budget,
-        solve_states_budget: states_budget,
-    };
-    let session = Session::new(state.session().state().state().clone(), config);
-
-    session.solve().map(|solution| {
-        solution.and_then(|solution| {
-            solution
-                .raw_solution()
-                .iter()
-                .map(|snapshot| *snapshot.instruction())
-                .find(|instruction| !instruction.is_useless())
-        })
-    })
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    /// `SolveError` has no `PartialEq`, so compare the winnable verdict and the
-    /// extracted first move (both `Eq`) rather than the whole `Result`.
-    fn verdict_key(outcome: &SolveOutcome) -> (bool, Option<KlondikeInstruction>) {
-        (outcome.is_err(), outcome.clone().ok().flatten())
-    }
-
-    #[test]
-    fn try_solve_is_deterministic() {
-        let a = try_solve(7, DrawMode::DrawOne, DEFAULT_SOLVE_MOVES_BUDGET, DEFAULT_SOLVE_STATES_BUDGET);
-        let b = try_solve(7, DrawMode::DrawOne, DEFAULT_SOLVE_MOVES_BUDGET, DEFAULT_SOLVE_STATES_BUDGET);
-        assert_eq!(verdict_key(&a), verdict_key(&b));
-    }
-
-    #[test]
-    fn winnable_verdict_carries_a_first_move() {
-        // Contract: a first move is present iff the verdict is winnable.
-        let outcome = try_solve(7, DrawMode::DrawOne, 5_000, 5_000);
-        let winnable = matches!(outcome, Ok(Some(_)));
-        let has_move = outcome.ok().flatten().is_some();
-        assert_eq!(winnable, has_move);
-    }
-
-    #[test]
-    fn try_solve_from_state_uses_live_game_state() {
-        let mut game = GameState::new(42, DrawMode::DrawOne);
-        game.draw().expect("draw must succeed");
-
-        let outcome = try_solve_from_state(&game, 5_000, 5_000);
-        let winnable = matches!(outcome, Ok(Some(_)));
-        let has_move = outcome.ok().flatten().is_some();
-        assert_eq!(winnable, has_move);
-    }
-
-    #[test]
-    fn zero_state_budget_is_inconclusive() {
-        let outcome = try_solve(7, DrawMode::DrawOne, 5_000, 0);
-        assert!(matches!(outcome, Err(SolveError::StatesBudgetExceeded)));
-    }
-
-    #[test]
-    fn budget_is_passed_through_not_clamped() {
-        // This seed is Inconclusive at 1k states but Winnable at 5k — proving
-        // the budget reaches the solver unchanged.
-        let easy = try_solve(0xD1FF_0000_0000_0012, DrawMode::DrawOne, 1_000, 1_000);
-        let medium = try_solve(0xD1FF_0000_0000_0012, DrawMode::DrawOne, 5_000, 5_000);
-        assert!(easy.is_err());
-        assert!(matches!(medium, Ok(Some(_))));
-    }
-
-    #[test]
-    fn budget_above_five_thousand_is_not_clamped() {
-        let below_cap = try_solve(0xD1FF_0000_0000_00DE, DrawMode::DrawOne, 5_000, 5_000);
-        let above_cap = try_solve(0xD1FF_0000_0000_00DE, DrawMode::DrawOne, 50_000, 50_000);
-        assert!(below_cap.is_err(), "seed must be Inconclusive at 5 000 states");
-        assert!(
-            matches!(above_cap, Ok(Some(_))),
-            "seed must be Winnable at 50 000 states — re-introducing the 5k cap would break this"
-        );
-    }
-}

solitaire_data/src/stats.rs

@@ -2,10 +2,10 @@
 //!
 //! [`StatsSnapshot`] is defined in `solitaire_sync` and re-exported here.
 //! This module adds the [`StatsExt`] extension trait, which supplies the
-//! `update_on_win` method that depends on [`DrawMode`] from `solitaire_core`.
+//! `update_on_win` method that depends on [`DrawStockConfig`] from `solitaire_core`.
 
 use chrono::Utc;
-use solitaire_core::{DrawMode, game_state::GameMode};
+use solitaire_core::{DrawStockConfig, game_state::GameMode};
 
 pub use solitaire_sync::StatsSnapshot;
 
@@ -18,9 +18,9 @@ pub trait StatsExt {
     ///
     /// Tracks lifetime totals only — per-mode best scores and times are
     /// updated separately via [`StatsExt::update_per_mode_bests`] so the
-    /// long-standing call sites that only know about [`DrawMode`] keep
+    /// long-standing call sites that only know about [`DrawStockConfig`] keep
     /// compiling.
-    fn update_on_win(&mut self, score: i32, time_seconds: u64, draw_mode: &DrawMode);
+    fn update_on_win(&mut self, score: i32, time_seconds: u64, draw_mode: &DrawStockConfig);
 
     /// Updates the per-mode best score and fastest-win-time fields for the
     /// given [`GameMode`]. Call alongside [`StatsExt::update_on_win`] from
@@ -37,7 +37,7 @@ pub trait StatsExt {
 }
 
 impl StatsExt for StatsSnapshot {
-    fn update_on_win(&mut self, score: i32, time_seconds: u64, draw_mode: &DrawMode) {
+    fn update_on_win(&mut self, score: i32, time_seconds: u64, draw_mode: &DrawStockConfig) {
         let prev_wins = self.games_won;
         self.games_played += 1;
         self.games_won += 1;
@@ -64,8 +64,8 @@ impl StatsExt for StatsSnapshot {
         };
 
         match draw_mode {
-            DrawMode::DrawOne => self.draw_one_wins += 1,
+            DrawStockConfig::DrawOne => self.draw_one_wins += 1,
-            DrawMode::DrawThree => self.draw_three_wins += 1,
+            DrawStockConfig::DrawThree => self.draw_three_wins += 1,
         }
 
         self.last_modified = Utc::now();
@@ -135,7 +135,7 @@ mod tests {
     #[test]
     fn first_win_sets_all_fields() {
         let mut s = StatsSnapshot::default();
-        s.update_on_win(1500, 120, &DrawMode::DrawOne);
+        s.update_on_win(1500, 120, &DrawStockConfig::DrawOne);
         assert_eq!(s.games_played, 1);
         assert_eq!(s.games_won, 1);
         assert_eq!(s.win_streak_current, 1);
@@ -152,7 +152,7 @@ mod tests {
     fn streak_tracks_across_wins() {
         let mut s = StatsSnapshot::default();
         for _ in 0..3 {
-            s.update_on_win(100, 60, &DrawMode::DrawOne);
+            s.update_on_win(100, 60, &DrawStockConfig::DrawOne);
         }
         assert_eq!(s.win_streak_current, 3);
         assert_eq!(s.win_streak_best, 3);
@@ -161,8 +161,8 @@ mod tests {
     #[test]
     fn record_abandoned_resets_streak_and_increments_played() {
         let mut s = StatsSnapshot::default();
-        s.update_on_win(100, 60, &DrawMode::DrawOne);
+        s.update_on_win(100, 60, &DrawStockConfig::DrawOne);
-        s.update_on_win(100, 60, &DrawMode::DrawOne);
+        s.update_on_win(100, 60, &DrawStockConfig::DrawOne);
         assert_eq!(s.win_streak_current, 2);
         s.record_abandoned();
         assert_eq!(s.games_played, 3);
@@ -174,35 +174,35 @@ mod tests {
     #[test]
     fn fastest_win_takes_minimum() {
         let mut s = StatsSnapshot::default();
-        s.update_on_win(100, 300, &DrawMode::DrawOne);
+        s.update_on_win(100, 300, &DrawStockConfig::DrawOne);
-        s.update_on_win(100, 120, &DrawMode::DrawOne);
+        s.update_on_win(100, 120, &DrawStockConfig::DrawOne);
-        s.update_on_win(100, 500, &DrawMode::DrawOne);
+        s.update_on_win(100, 500, &DrawStockConfig::DrawOne);
         assert_eq!(s.fastest_win_seconds, 120);
     }
 
     #[test]
     fn avg_time_is_correct_rolling_average() {
         let mut s = StatsSnapshot::default();
-        s.update_on_win(100, 100, &DrawMode::DrawOne);
+        s.update_on_win(100, 100, &DrawStockConfig::DrawOne);
-        s.update_on_win(100, 200, &DrawMode::DrawOne);
+        s.update_on_win(100, 200, &DrawStockConfig::DrawOne);
-        s.update_on_win(100, 300, &DrawMode::DrawOne);
+        s.update_on_win(100, 300, &DrawStockConfig::DrawOne);
         assert_eq!(s.avg_time_seconds, 200);
     }
 
     #[test]
     fn best_score_updates_only_on_higher_score() {
         let mut s = StatsSnapshot::default();
-        s.update_on_win(500, 60, &DrawMode::DrawOne);
+        s.update_on_win(500, 60, &DrawStockConfig::DrawOne);
-        s.update_on_win(300, 60, &DrawMode::DrawOne);
+        s.update_on_win(300, 60, &DrawStockConfig::DrawOne);
         assert_eq!(s.best_single_score, 500);
-        s.update_on_win(800, 60, &DrawMode::DrawOne);
+        s.update_on_win(800, 60, &DrawStockConfig::DrawOne);
         assert_eq!(s.best_single_score, 800);
     }
 
     #[test]
     fn negative_score_treated_as_zero() {
         let mut s = StatsSnapshot::default();
-        s.update_on_win(-50, 60, &DrawMode::DrawOne);
+        s.update_on_win(-50, 60, &DrawStockConfig::DrawOne);
         assert_eq!(s.best_single_score, 0);
         assert_eq!(s.lifetime_score, 0);
     }
@@ -210,8 +210,8 @@ mod tests {
     #[test]
     fn draw_three_wins_tracked_separately() {
         let mut s = StatsSnapshot::default();
-        s.update_on_win(100, 60, &DrawMode::DrawOne);
+        s.update_on_win(100, 60, &DrawStockConfig::DrawOne);
-        s.update_on_win(100, 60, &DrawMode::DrawThree);
+        s.update_on_win(100, 60, &DrawStockConfig::DrawThree);
         assert_eq!(s.draw_one_wins, 1);
         assert_eq!(s.draw_three_wins, 1);
     }
@@ -221,7 +221,7 @@ mod tests {
         let mut s = StatsSnapshot::default();
         // Build a streak of 5.
         for _ in 0..5 {
-            s.update_on_win(100, 60, &DrawMode::DrawOne);
+            s.update_on_win(100, 60, &DrawStockConfig::DrawOne);
         }
         assert_eq!(s.win_streak_best, 5);
         // Lose (abandon), resetting current.
@@ -229,7 +229,7 @@ mod tests {
         assert_eq!(s.win_streak_current, 0);
         assert_eq!(s.win_streak_best, 5, "best must survive the loss");
         // Win once — current becomes 1, best must remain 5.
-        s.update_on_win(100, 60, &DrawMode::DrawOne);
+        s.update_on_win(100, 60, &DrawStockConfig::DrawOne);
         assert_eq!(s.win_streak_current, 1);
         assert_eq!(
             s.win_streak_best, 5,
@@ -243,7 +243,7 @@ mod tests {
             lifetime_score: u64::MAX - 100,
             ..Default::default()
         };
-        s.update_on_win(200, 60, &DrawMode::DrawOne);
+        s.update_on_win(200, 60, &DrawStockConfig::DrawOne);
         assert_eq!(
             s.lifetime_score,
             u64::MAX,

solitaire_data/src/storage.rs

@@ -279,7 +279,7 @@ fn cleanup_tmp_files_in(dir: &Path) {
 mod tests {
     use super::*;
     use crate::stats::{StatsExt, StatsSnapshot};
-    use solitaire_core::DrawMode;
+    use solitaire_core::DrawStockConfig;
     use std::env;
 
     fn tmp_path(name: &str) -> PathBuf {
@@ -292,7 +292,7 @@ mod tests {
         let _ = fs::remove_file(&path);
 
         let mut stats = StatsSnapshot::default();
-        stats.update_on_win(1000, 180, &DrawMode::DrawOne);
+        stats.update_on_win(1000, 180, &DrawStockConfig::DrawOne);
         save_stats_to(&path, &stats).expect("save");
 
         let loaded = load_stats_from(&path);
@@ -381,7 +381,7 @@ mod tests {
         let path = gs_path("round_trip");
         let _ = fs::remove_file(&path);
 
-        let gs = GameState::new(12345, DrawMode::DrawOne);
+        let gs = GameState::new(12345, DrawStockConfig::DrawOne);
         save_game_state_to(&path, &gs).expect("save");
 
         let loaded = load_game_state_from(&path).expect("load");
@@ -410,7 +410,7 @@ mod tests {
         let path = gs_path("won_skip");
         let _ = fs::remove_file(&path);
 
-        let mut gs = GameState::new(99, DrawMode::DrawOne);
+        let mut gs = GameState::new(99, DrawStockConfig::DrawOne);
         gs.set_test_won(true);
         save_game_state_to(&path, &gs).expect("save should be no-op, not error");
         assert!(
@@ -423,7 +423,7 @@ mod tests {
     fn delete_game_state_removes_file() {
         use solitaire_core::game_state::GameState;
         let path = gs_path("delete");
-        let gs = GameState::new(1, DrawMode::DrawOne);
+        let gs = GameState::new(1, DrawStockConfig::DrawOne);
         save_game_state_to(&path, &gs).expect("save");
         assert!(path.exists());
         delete_game_state_at(&path).expect("delete");
@@ -441,7 +441,7 @@ mod tests {
     fn save_game_state_is_atomic() {
         use solitaire_core::game_state::GameState;
         let path = gs_path("atomic");
-        let gs = GameState::new(55, DrawMode::DrawThree);
+        let gs = GameState::new(55, DrawStockConfig::DrawThree);
         save_game_state_to(&path, &gs).expect("save");
         let tmp = path.with_extension("json.tmp");
         assert!(!tmp.exists(), ".tmp must be cleaned up after rename");
@@ -497,22 +497,22 @@ mod tests {
     /// replays all `saved_moves` to reconstruct every pile.
     ///
     /// A fresh-game test (zero moves) never exercises that replay path, so this
-    /// test plays several real moves — including an undo — before saving, then
+    /// test plays several real moves — including an undo — before saving.
-    /// asserts the full pile layout round-trips exactly.
     ///
-    /// `GameState::PartialEq` covers stock, waste, all four foundations, all
+    /// Since schema v5 no longer persists `score`/`undo_count`/`recycle_count`
-    /// seven tableau columns, `score`, `move_count`, `undo_count`, and
+    /// (they are derived from the replayed session stats), round-trip fidelity is
-    /// `recycle_count`. Any breakage in the upstream serde or replay path
+    /// verified by **re-save idempotency**: reloading the save and serialising it
-    /// will cause at least one pile to disagree.
+    /// again must reproduce byte-identical JSON. `undo_count` deliberately resets
+    /// to 0 on load because only the forward instruction history is persisted.
     #[test]
-    fn game_state_v4_mid_game_round_trip() {
+    fn game_state_v5_mid_game_round_trip() {
         use solitaire_core::KlondikeInstruction;
         use solitaire_core::game_state::GameState;
 
         let path = gs_path("v4_mid_game");
         let _ = fs::remove_file(&path);
 
-        let mut gs = GameState::new(42, DrawMode::DrawOne);
+        let mut gs = GameState::new(42, DrawStockConfig::DrawOne);
 
         // Draw several times to populate the instruction history with
         // RotateStock entries and expose waste cards for further moves.
@@ -546,19 +546,40 @@ mod tests {
 
         save_game_state_to(&path, &gs).expect("save");
 
-        // Verify the file contains the v4 schema marker (tolerates pretty-print whitespace).
+        // Verify the file carries the v5 schema marker.
         let json = fs::read_to_string(&path).expect("read json");
         assert!(
-            json.contains("schema_version") && json.contains('4') && !json.contains(": 3"),
+            json.contains("\"schema_version\"") && json.contains('5'),
-            "saved file must use schema version 4",
+            "saved file must use schema version 5",
         );
 
         let loaded = load_game_state_from(&path)
             .expect("a valid in-progress game must load without error");
 
+        // The forward instruction history round-trips, so the reconstructed board
+        // re-serialises to byte-identical JSON.
+        let path_reload = gs_path("v5_mid_game_reload");
+        let _ = fs::remove_file(&path_reload);
+        save_game_state_to(&path_reload, &loaded).expect("re-save loaded");
         assert_eq!(
-            loaded, gs,
+            fs::read_to_string(&path).expect("read original save"),
-            "all pile layouts and counters must be identical after schema-v4 round-trip",
+            fs::read_to_string(&path_reload).expect("read re-saved"),
+            "re-saving the loaded game must reproduce the original save exactly",
+        );
+
+        // Derived board reads match the live game (move count + recycle count are
+        // both rebuilt from the replayed forward history).
+        assert_eq!(loaded.move_count(), gs.move_count(), "move_count round-trips");
+        assert_eq!(
+            loaded.recycle_count(),
+            gs.recycle_count(),
+            "recycle_count round-trips",
+        );
+        // undo_count is intentionally not persisted: it resets to 0 on load.
+        assert_eq!(
+            loaded.undo_count(),
+            0,
+            "undo_count resets across save/load under schema v5",
         );
     }
 
@@ -598,7 +619,7 @@ mod tests {
             .expect("schema v3 must be accepted and migrated to v4");
 
         // The loaded game should match a fresh game that had one draw applied.
-        let mut expected = GameState::new(42, DrawMode::DrawOne);
+        let mut expected = GameState::new(42, DrawStockConfig::DrawOne);
         expected.draw().expect("draw must succeed on a fresh game");
         assert_eq!(loaded, expected, "migrated v3 game state must match equivalent v4 state");
     }

solitaire_data/src/weekly.rs

@@ -4,7 +4,7 @@
 //! increments matching counters in `PlayerProgress::weekly_goal_progress`.
 
 use chrono::{Datelike, NaiveDate};
-use solitaire_core::DrawMode;
+use solitaire_core::DrawStockConfig;
 
 /// XP awarded each time a weekly goal is just completed.
 pub const WEEKLY_GOAL_XP: u64 = 75;
@@ -36,7 +36,7 @@ pub struct WeeklyGoalDef {
 pub struct WeeklyGoalContext {
     pub time_seconds: u64,
     pub used_undo: bool,
-    pub draw_mode: DrawMode,
+    pub draw_mode: DrawStockConfig,
 }
 
 impl WeeklyGoalDef {
@@ -47,7 +47,7 @@ impl WeeklyGoalDef {
             WeeklyGoalKind::WinGame => true,
             WeeklyGoalKind::WinWithoutUndo => !ctx.used_undo,
             WeeklyGoalKind::WinUnder { seconds } => ctx.time_seconds < seconds,
-            WeeklyGoalKind::WinDrawThree => ctx.draw_mode == DrawMode::DrawThree,
+            WeeklyGoalKind::WinDrawThree => ctx.draw_mode == DrawStockConfig::DrawThree,
         }
     }
 }
@@ -106,7 +106,7 @@ mod tests {
         WeeklyGoalContext {
             time_seconds: time,
             used_undo: undo,
-            draw_mode: DrawMode::DrawOne,
+            draw_mode: DrawStockConfig::DrawOne,
         }
     }
 
@@ -114,7 +114,7 @@ mod tests {
         WeeklyGoalContext {
             time_seconds: time,
             used_undo: false,
-            draw_mode: DrawMode::DrawThree,
+            draw_mode: DrawStockConfig::DrawThree,
         }
     }
 

solitaire_engine/src/achievement_plugin.rs

@@ -176,9 +176,9 @@ fn evaluate_on_win(
             daily_challenge_streak: progress.0.daily_challenge_streak,
             last_win_score: ev.score,
             last_win_time_seconds: ev.time_seconds,
-            last_win_used_undo: game.0.undo_count > 0,
+            last_win_used_undo: game.0.undo_count() > 0,
             wall_clock_hour: Some(Local::now().hour()),
-            last_win_recycle_count: game.0.recycle_count,
+            last_win_recycle_count: game.0.recycle_count(),
             last_win_is_zen: game.0.mode == solitaire_core::game_state::GameMode::Zen,
         };
 
@@ -779,7 +779,7 @@ mod tests {
         app.world_mut()
             .resource_mut::<GameStateResource>()
             .0
-            .undo_count = 1;
+            .force_test_undos(1);
 
         app.world_mut().write_message(GameWonEvent {
             score: 1000,
@@ -819,7 +819,7 @@ mod tests {
         app.world_mut()
             .resource_mut::<GameStateResource>()
             .0
-            .set_test_draw_mode(solitaire_core::DrawMode::DrawThree);
+            .set_test_draw_mode(solitaire_core::DrawStockConfig::DrawThree);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,
@@ -868,7 +868,7 @@ mod tests {
         app.world_mut()
             .resource_mut::<GameStateResource>()
             .0
-            .set_test_draw_mode(solitaire_core::DrawMode::DrawThree);
+            .set_test_draw_mode(solitaire_core::DrawStockConfig::DrawThree);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,
@@ -1393,7 +1393,7 @@ mod tests {
 
     use crate::replay_playback::ReplayPlaybackState;
     use chrono::NaiveDate;
-    use solitaire_core::{DrawMode, game_state::GameMode};
+    use solitaire_core::{DrawStockConfig, game_state::GameMode};
     use solitaire_data::{Replay, ReplayMove};
 
     /// Headless app variant that injects a default `ReplayPlaybackState`
@@ -1409,7 +1409,7 @@ mod tests {
     fn dummy_replay() -> Replay {
         Replay::new(
             1,
-            DrawMode::DrawOne,
+            DrawStockConfig::DrawOne,
             GameMode::Classic,
             10,
             100,

solitaire_engine/src/assets/card_face_svg.rs

@@ -22,7 +22,7 @@
 //! red/black colour split.
 
 use bevy::math::UVec2;
-use solitaire_core::card::{Rank, Suit};
+use solitaire_core::{Rank, Suit};
 
 /// Target rasterisation size in pixels (2:3 aspect, half the default
 /// `SvgLoaderSettings` resolution).

solitaire_engine/src/auto_complete_plugin.rs

@@ -168,8 +168,8 @@ mod tests {
     use crate::game_plugin::GamePlugin;
     use crate::table_plugin::TablePlugin;
     use solitaire_core::{Foundation, KlondikePile, Tableau};
-    use solitaire_core::card::{Deck, Rank, Suit};
+    use solitaire_core::{Deck, Rank, Suit};
-    use solitaire_core::{DrawMode, game_state::GameState};
+    use solitaire_core::{DrawStockConfig, game_state::GameState};
 
     fn headless_app() -> App {
         let mut app = App::new();
@@ -183,7 +183,7 @@ mod tests {
     }
 
     fn seeded_state_with_auto_move() -> (GameState, (KlondikePile, KlondikePile)) {
-        let mut g = GameState::new(1, DrawMode::DrawOne);
+        let mut g = GameState::new(1, DrawStockConfig::DrawOne);
         g.set_test_stock_cards(Vec::new());
         g.set_test_waste_cards(Vec::new());
         for foundation in [
@@ -207,7 +207,7 @@ mod tests {
         }
         g.set_test_tableau_cards(
             Tableau::Tableau1,
-            vec![solitaire_core::card::Card::new(Deck::Deck1, Suit::Clubs, Rank::Ace)],
+            vec![solitaire_core::Card::new(Deck::Deck1, Suit::Clubs, Rank::Ace)],
         );
         g.set_test_auto_completable(true);
         let expected = (
@@ -227,7 +227,7 @@ mod tests {
     #[test]
     fn detect_activates_when_auto_completable() {
         let mut app = headless_app();
-        let mut g = GameState::new(42, DrawMode::DrawOne);
+        let mut g = GameState::new(42, DrawStockConfig::DrawOne);
         g.set_test_auto_completable(true);
         app.world_mut().resource_mut::<GameStateResource>().0 = g;
         app.world_mut().write_message(StateChangedEvent);

solitaire_engine/src/card_animation/interaction.rs

@@ -33,7 +33,7 @@ use std::collections::VecDeque;
 
 use bevy::prelude::*;
 use bevy::window::PrimaryWindow;
-use solitaire_core::card::Card;
+use solitaire_core::Card;
 
 use super::animation::CardAnimation;
 use super::tuning::AnimationTuning;

solitaire_engine/src/card_plugin.rs

@@ -17,8 +17,8 @@ use bevy::prelude::*;
 use bevy::sprite::Anchor;
 use bevy::window::WindowResized;
 use solitaire_core::{Foundation, KlondikePile, Tableau};
-use solitaire_core::card::{Card, Rank, Suit};
+use solitaire_core::{Card, Rank, Suit};
-use solitaire_core::{DrawMode, game_state::GameState};
+use solitaire_core::{DrawStockConfig, game_state::GameState};
 
 use crate::animation_plugin::{CARD_ANIM_Z_LIFT, CardAnim, EffectiveSlideDuration};
 use crate::card_animation::CardAnimation;
@@ -789,8 +789,8 @@ fn sync_cards(
     // and its rank/suit peek behind the incoming card.
     let waste_buffer_id: Option<Card> = {
         let visible = match game.draw_mode() {
-            DrawMode::DrawOne => 1_usize,
+            DrawStockConfig::DrawOne => 1_usize,
-            DrawMode::DrawThree => 3_usize,
+            DrawStockConfig::DrawThree => 3_usize,
         };
         let waste_cards = game.waste_cards();
         (waste_cards.len() > visible)
@@ -958,8 +958,8 @@ fn card_positions(game: &GameState, layout: &Layout) -> Vec<((Card, bool), Vec2,
         // shows up to 3 fanned in X (matching the standard Klondike presentation).
         let render_start = if is_waste {
             let visible = match game.draw_mode() {
-                DrawMode::DrawOne => 1_usize,
+                DrawStockConfig::DrawOne => 1_usize,
-                DrawMode::DrawThree => 3_usize,
+                DrawStockConfig::DrawThree => 3_usize,
             };
             // Render one extra card so that the card sliding off the waste
             // during a draw animation is still present in the world at z=0
@@ -972,7 +972,7 @@ fn card_positions(game: &GameState, layout: &Layout) -> Vec<((Card, bool), Vec2,
         let mut y_offset = 0.0_f32;
         let rendered_len = cards[render_start..].len();
         for (slot, (card, face_up)) in cards[render_start..].iter().enumerate() {
-            let x_offset = if is_waste && matches!(game.draw_mode(), DrawMode::DrawThree) {
+            let x_offset = if is_waste && matches!(game.draw_mode(), DrawStockConfig::DrawThree) {
                 // When len > visible, slot 0 is a hidden buffer card kept at
                 // x=0 to prevent a flash during the draw tween. When len ≤
                 // visible (small pile), every card is visible and should fan
@@ -1487,6 +1487,7 @@ fn update_drag_shadow(
     drag: Res<DragState>,
     layout: Option<Res<LayoutResource>>,
     card_entities: Query<(&CardEntity, &Transform)>,
+    card_index: Res<CardEntityIndex>,
     mut shadow: Local<Option<Entity>>,
 ) {
     if drag.is_idle() {
@@ -1503,9 +1504,9 @@ fn update_drag_shadow(
 
     // Find the world position of the first (top) dragged card.
     let top_pos = drag.cards.first().and_then(|first_card| {
-        card_entities
+        card_index
-            .iter()
+            .get(first_card)
-            .find(|(marker, _)| marker.card == *first_card)
+            .and_then(|entity| card_entities.get(entity).ok())
             .map(|(_, t)| t.translation)
     });
 
@@ -2471,7 +2472,7 @@ mod tests {
     use super::*;
     use crate::game_plugin::GamePlugin;
     use crate::table_plugin::TablePlugin;
-    use solitaire_core::card::Deck;
+    use solitaire_core::Deck;
 
     /// Convenience constructor — all unit tests use Deck1.
     fn make_card(suit: Suit, rank: Rank) -> Card {
@@ -2565,7 +2566,7 @@ mod tests {
     #[test]
     fn card_positions_includes_all_52_cards_at_game_start() {
         // At game start waste is empty, so all 52 cards are across stock + tableau.
-        let g = GameState::new(42, solitaire_core::DrawMode::DrawOne);
+        let g = GameState::new(42, solitaire_core::DrawStockConfig::DrawOne);
         let layout = crate::layout::compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0, true);
         let positions = card_positions(&g, &layout);
         assert_eq!(positions.len(), 52);
@@ -2573,8 +2574,8 @@ mod tests {
 
     #[test]
     fn waste_draw_one_only_renders_top_card() {
-        use solitaire_core::DrawMode;
+        use solitaire_core::DrawStockConfig;
-        let mut g = GameState::new(42, DrawMode::DrawOne);
+        let mut g = GameState::new(42, DrawStockConfig::DrawOne);
         // Draw 3 cards so the waste pile has 3 cards.
         for _ in 0..3 {
             let _ = g.draw();
@@ -2611,8 +2612,8 @@ mod tests {
 
     #[test]
     fn waste_draw_three_renders_up_to_three_fanned_cards() {
-        use solitaire_core::DrawMode;
+        use solitaire_core::DrawStockConfig;
-        let mut g = GameState::new(42, DrawMode::DrawThree);
+        let mut g = GameState::new(42, DrawStockConfig::DrawThree);
         // 5 draw() calls in Draw-Three mode accumulates multiple waste cards.
         for _ in 0..5 {
             let _ = g.draw();
@@ -2665,8 +2666,8 @@ mod tests {
         // Regression: slot.saturating_sub(1) always hid slot-0 even when the
         // pile was too small to have a buffer card, collapsing 2 visible cards
         // onto x=0 instead of fanning them.
-        use solitaire_core::DrawMode;
+        use solitaire_core::DrawStockConfig;
-        let mut g = GameState::new(42, DrawMode::DrawThree);
+        let mut g = GameState::new(42, DrawStockConfig::DrawThree);
         // Draw exactly once — in Draw-Three mode with a full stock this gives
         // 3 waste cards (still ≤ visible=3, so no hidden buffer needed).
         let _ = g.draw();
@@ -2708,8 +2709,8 @@ mod tests {
     /// top card so that hiding it (`Visibility::Hidden`) leaves no visible gap.
     #[test]
     fn waste_draw_one_buffer_card_at_same_xy_as_top() {
-        use solitaire_core::DrawMode;
+        use solitaire_core::DrawStockConfig;
-        let mut g = GameState::new(42, DrawMode::DrawOne);
+        let mut g = GameState::new(42, DrawStockConfig::DrawOne);
         // Draw 3 times so the waste pile has 3 cards and the buffer exists.
         for _ in 0..3 {
             let _ = g.draw();
@@ -2739,7 +2740,7 @@ mod tests {
 
     #[test]
     fn card_positions_tableau_cards_are_fanned_downward() {
-        let g = GameState::new(42, solitaire_core::DrawMode::DrawOne);
+        let g = GameState::new(42, solitaire_core::DrawStockConfig::DrawOne);
         let layout = crate::layout::compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0, true);
         let positions = card_positions(&g, &layout);
 
@@ -3082,7 +3083,7 @@ mod tests {
 
     #[test]
     fn facedown_cards_use_tighter_fan_than_uniform_faceup_fan() {
-        let g = GameState::new(42, solitaire_core::DrawMode::DrawOne);
+        let g = GameState::new(42, solitaire_core::DrawStockConfig::DrawOne);
         let layout = crate::layout::compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0, true);
         let positions = card_positions(&g, &layout);
 
@@ -3532,7 +3533,7 @@ mod tests {
 
     #[test]
     fn stock_card_count_helper_reads_zero_for_empty_stock() {
-        let g = GameState::new(42, solitaire_core::DrawMode::DrawOne);
+        let g = GameState::new(42, solitaire_core::DrawStockConfig::DrawOne);
         let mut g_empty_stock = g.clone();
         g_empty_stock.set_test_stock_cards(Vec::new());
         assert_eq!(stock_card_count(&g_empty_stock), 0);
@@ -3804,8 +3805,8 @@ mod tests {
 
     #[test]
     fn waste_pile_cards_have_strictly_increasing_z() {
-        use solitaire_core::DrawMode;
+        use solitaire_core::DrawStockConfig;
-        let mut g = GameState::new(42, DrawMode::DrawThree);
+        let mut g = GameState::new(42, DrawStockConfig::DrawThree);
         for _ in 0..5 {
             let _ = g.draw();
         }
@@ -3848,8 +3849,8 @@ mod tests {
     /// offsets or flips the fan direction is caught immediately.
     #[test]
     fn waste_cards_do_not_overlap_stock_column_on_portrait() {
-        use solitaire_core::DrawMode;
+        use solitaire_core::DrawStockConfig;
-        let mut g = GameState::new(42, DrawMode::DrawThree);
+        let mut g = GameState::new(42, DrawStockConfig::DrawThree);
         for _ in 0..5 {
             let _ = g.draw();
         }
@@ -3884,8 +3885,8 @@ mod tests {
 
     #[test]
     fn waste_pile_draw_one_cards_have_distinct_z() {
-        use solitaire_core::DrawMode;
+        use solitaire_core::DrawStockConfig;
-        let mut g = GameState::new(42, DrawMode::DrawOne);
+        let mut g = GameState::new(42, DrawStockConfig::DrawOne);
         for _ in 0..3 {
             let _ = g.draw();
         }

solitaire_engine/src/challenge_plugin.rs

@@ -117,7 +117,7 @@ mod tests {
     use crate::game_plugin::GamePlugin;
     use crate::progress_plugin::ProgressPlugin;
     use crate::table_plugin::TablePlugin;
-    use solitaire_core::{DrawMode, game_state::GameState};
+    use solitaire_core::{DrawStockConfig, game_state::GameState};
 
     fn headless_app() -> App {
         let mut app = App::new();
@@ -135,7 +135,7 @@ mod tests {
     fn challenge_win_advances_index() {
         let mut app = headless_app();
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new_with_mode(1, DrawMode::DrawOne, GameMode::Challenge);
+            GameState::new_with_mode(1, DrawStockConfig::DrawOne, GameMode::Challenge);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,
@@ -224,7 +224,7 @@ mod tests {
             .0
             .challenge_index = 2;
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new_with_mode(1, DrawMode::DrawOne, GameMode::Challenge);
+            GameState::new_with_mode(1, DrawStockConfig::DrawOne, GameMode::Challenge);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,

solitaire_engine/src/cursor_plugin.rs

@@ -34,9 +34,9 @@
 
 use bevy::prelude::*;
 use bevy::window::{CursorIcon, PrimaryWindow, SystemCursorIcon};
-use solitaire_core::card::Card;
+use solitaire_core::Card;
 use solitaire_core::{Foundation, KlondikePile, Tableau};
-use solitaire_core::{DrawMode, game_state::GameState};
+use solitaire_core::{DrawStockConfig, game_state::GameState};
 
 use crate::card_plugin::RightClickHighlight;
 use crate::layout::{Layout, LayoutResource};
@@ -437,7 +437,7 @@ fn tableau_or_stack_pos(
             base.x,
             base.y - layout.card_size.y * layout.tableau_fan_frac * (index as f32),
         )
-    } else if matches!(pile, KlondikePile::Stock) && game.draw_mode() == DrawMode::DrawThree {
+    } else if matches!(pile, KlondikePile::Stock) && game.draw_mode() == DrawStockConfig::DrawThree {
         let pile_len = game.waste_cards().len();
         let visible_start = pile_len.saturating_sub(3);
         let slot = index.saturating_sub(visible_start) as f32;
@@ -563,9 +563,9 @@ mod tests {
     #[test]
     fn cursor_over_draggable_returns_false_for_empty_game() {
         use crate::layout::compute_layout;
-        use solitaire_core::{DrawMode, game_state::GameState};
+        use solitaire_core::{DrawStockConfig, game_state::GameState};
 
-        let game = GameState::new(42, DrawMode::DrawOne);
+        let game = GameState::new(42, DrawStockConfig::DrawOne);
         let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0, true);
         // A cursor far off-screen should never hit anything.
         assert!(!cursor_over_draggable(
@@ -580,8 +580,8 @@ mod tests {
     // -----------------------------------------------------------------------
 
     use crate::layout::compute_layout;
-    use solitaire_core::card::{Card, Deck, Rank, Suit};
+    use solitaire_core::{Card, Deck, Rank, Suit};
-    use solitaire_core::{DrawMode, game_state::{GameMode, GameState}};
+    use solitaire_core::{DrawStockConfig, game_state::{GameMode, GameState}};
 
     /// Builds an `App` with `MinimalPlugins` and the overlay system
     /// registered, plus the resources the system needs. Callers
@@ -629,7 +629,7 @@ mod tests {
         // 5 of Spades (black) onto Tableau(2)'s 6 of Clubs (also black)
         // — same colour family, illegal. Tableau(2) must NOT be
         // highlighted.
-        let mut game = GameState::new_with_mode(7, DrawMode::DrawOne, GameMode::Classic);
+        let mut game = GameState::new_with_mode(7, DrawStockConfig::DrawOne, GameMode::Classic);
         set_tableau_top(
             &mut game,
             2,

solitaire_engine/src/daily_challenge_plugin.rs

@@ -362,7 +362,7 @@ mod tests {
     use crate::progress_plugin::ProgressPlugin;
     use crate::table_plugin::TablePlugin;
     #[allow(unused_imports)]
-    use solitaire_core::{DrawMode, game_state::GameState};
+    use solitaire_core::{DrawStockConfig, game_state::GameState};
 
     fn headless_app() -> App {
         let mut app = App::new();
@@ -391,7 +391,7 @@ mod tests {
 
         // Replace the GameState with one whose seed matches the daily seed.
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new(daily_seed, DrawMode::DrawOne);
+            GameState::new(daily_seed, DrawStockConfig::DrawOne);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,
@@ -419,7 +419,7 @@ mod tests {
         let daily_seed = app.world().resource::<DailyChallengeResource>().seed;
         // Use a deliberately different seed.
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new(daily_seed.wrapping_add(7777), DrawMode::DrawOne);
+            GameState::new(daily_seed.wrapping_add(7777), DrawStockConfig::DrawOne);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,
@@ -442,7 +442,7 @@ mod tests {
         let mut app = headless_app();
         let daily_seed = app.world().resource::<DailyChallengeResource>().seed;
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new(daily_seed, DrawMode::DrawOne);
+            GameState::new(daily_seed, DrawStockConfig::DrawOne);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,

solitaire_engine/src/events.rs

@@ -2,7 +2,7 @@
 
 use bevy::prelude::Message;
 use solitaire_core::KlondikePile;
-use solitaire_core::card::{Card, Suit};
+use solitaire_core::{Card, Suit};
 use solitaire_core::game_state::GameMode;
 use solitaire_data::AchievementRecord;
 use solitaire_sync::SyncResponse;

solitaire_engine/src/feedback_anim_plugin.rs

@@ -43,8 +43,9 @@ use std::hash::{Hash, Hasher};
 
 use bevy::prelude::*;
 use bevy::window::RequestRedraw;
-use solitaire_core::card::Card;
+use solitaire_core::Card;
-use solitaire_core::{Foundation, KlondikePile};
+use solitaire_core::KlondikePile;
+use solitaire_core::klondike_adapter::foundation_from_slot;
 use solitaire_data::AnimSpeed;
 
 use crate::animation_plugin::CardAnim;
@@ -188,10 +189,6 @@ pub fn deal_stagger_jitter(card_id: u32) -> f32 {
     (jitter_norm - 0.5) * 0.2 // ±0.1 == ±10 %
 }
 
-// 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
 // ---------------------------------------------------------------------------
@@ -412,10 +409,14 @@ fn start_deal_anim(
 
     for (index, (entity, card_marker, transform)) in card_entities.iter().enumerate() {
         let final_pos = transform.translation;
-        // ±10 % jitter, deterministic per card id, so the deal feels organic
+        // ±10 % jitter, deterministic per card, so the deal feels organic
-        // without losing reproducibility (a given seed still produces the
+        // without losing reproducibility (a given deal produces the same
-        // same per-card stagger pattern across runs).
+        // per-card stagger pattern across runs). The seed is a hash of the
-        let per_card_stagger = stagger_secs * (1.0 + deal_stagger_jitter(card_to_id(&card_marker.card)));
+        // card's own identity — no separate numeric id needed.
+        let mut card_hasher = DefaultHasher::new();
+        card_marker.card.hash(&mut card_hasher);
+        let per_card_stagger =
+            stagger_secs * (1.0 + deal_stagger_jitter(card_hasher.finish() as u32));
         commands.entity(entity).insert((
             Transform::from_translation(stock_start.with_z(final_pos.z)),
             CardAnim {
@@ -638,23 +639,13 @@ fn lerp_color(from: Color, to: Color, t: f32) -> Color {
 fn pile_cards(
     game: &solitaire_core::game_state::GameState,
     pile: &KlondikePile,
-) -> Vec<(solitaire_core::card::Card, bool)> {
+) -> Vec<(solitaire_core::Card, bool)> {
     match pile {
         KlondikePile::Stock => game.waste_cards(),
         _ => game.pile(*pile),
     }
 }
 
-fn foundation_from_slot(slot: u8) -> Option<Foundation> {
-    match slot {
-        0 => Some(Foundation::Foundation1),
-        1 => Some(Foundation::Foundation2),
-        2 => Some(Foundation::Foundation3),
-        3 => Some(Foundation::Foundation4),
-        _ => None,
-    }
-}
-
 // ---------------------------------------------------------------------------
 // Unit tests (pure functions only — no Bevy world required)
 // ---------------------------------------------------------------------------
@@ -855,13 +846,13 @@ mod tests {
     fn shake_anim_skipped_under_reduce_motion() {
         use bevy::ecs::message::Messages;
         use solitaire_core::Tableau;
-        use solitaire_core::{DrawMode, game_state::GameState};
+        use solitaire_core::{DrawStockConfig, game_state::GameState};
         use solitaire_data::Settings;
 
         let mut app = App::new();
         app.add_plugins(MinimalPlugins)
             .add_plugins(FeedbackAnimPlugin);
-        app.insert_resource(GameStateResource(GameState::new(1, DrawMode::DrawOne)));
+        app.insert_resource(GameStateResource(GameState::new(1, DrawStockConfig::DrawOne)));
         app.insert_resource(SettingsResource(Settings {
             reduce_motion_mode: true,
             ..Settings::default()
@@ -909,13 +900,13 @@ mod tests {
     #[test]
     fn foundation_flourish_skipped_under_reduce_motion() {
         use bevy::ecs::message::Messages;
-        use solitaire_core::{DrawMode, game_state::GameState};
+        use solitaire_core::{DrawStockConfig, game_state::GameState};
         use solitaire_data::Settings;
 
         let mut app = App::new();
         app.add_plugins(MinimalPlugins)
             .add_plugins(FeedbackAnimPlugin);
-        app.insert_resource(GameStateResource(GameState::new(1, DrawMode::DrawOne)));
+        app.insert_resource(GameStateResource(GameState::new(1, DrawStockConfig::DrawOne)));
         app.insert_resource(SettingsResource(Settings {
             reduce_motion_mode: true,
             ..Settings::default()
@@ -926,7 +917,7 @@ mod tests {
             .resource_mut::<Messages<FoundationCompletedEvent>>()
             .write(FoundationCompletedEvent {
                 slot: 0,
-                suit: solitaire_core::card::Suit::Spades,
+                suit: solitaire_core::Suit::Spades,
             });
         app.update();
 

solitaire_engine/src/game_plugin.rs

@@ -14,10 +14,8 @@ use bevy::prelude::*;
 use bevy::tasks::{AsyncComputeTaskPool, Task, futures_lite::future};
 use bevy::window::AppLifecycle;
 use solitaire_core::KlondikePile;
-use solitaire_core::{DrawMode, game_state::{GameMode, GameState}};
+use solitaire_core::{DrawStockConfig, game_state::{GameMode, GameState}};
-use solitaire_data::solver::{
+use solitaire_core::{DEFAULT_SOLVE_MOVES_BUDGET, DEFAULT_SOLVE_STATES_BUDGET};
-    DEFAULT_SOLVE_MOVES_BUDGET, DEFAULT_SOLVE_STATES_BUDGET, try_solve,
-};
 #[allow(deprecated)]
 use solitaire_data::latest_replay_path;
 use solitaire_data::{
@@ -159,12 +157,12 @@ impl Plugin for GamePlugin {
             .is_some_and(|g| g.move_count() > 0 && !g.is_won());
         let (initial_state, pending_restore) = if prompt_worthy {
             (
-                GameState::new(seed_from_system_time(), DrawMode::DrawOne),
+                GameState::new(seed_from_system_time(), DrawStockConfig::DrawOne),
                 saved,
             )
         } else {
             (
-                saved.unwrap_or_else(|| GameState::new(seed_from_system_time(), DrawMode::DrawOne)),
+                saved.unwrap_or_else(|| GameState::new(seed_from_system_time(), DrawStockConfig::DrawOne)),
                 None,
             )
         };
@@ -318,7 +316,7 @@ fn seed_from_system_time() -> u64 {
 }
 
 /// Walks forward from `initial_seed` (incrementing by 1 with wrapping
-/// arithmetic) until the [`solitaire_data::solver`] returns a verdict
+/// arithmetic) until the [`GameState::solve_fresh_deal`] returns a verdict
 /// the engine accepts as winnable, or until [`SOLVER_DEAL_RETRY_CAP`]
 /// attempts have elapsed.
 ///
@@ -390,10 +388,10 @@ fn poll_pending_new_game_seed(
 
 /// Pure helper extracted for testability — `new_game_with_solver_*`
 /// engine tests in the same file exercise this path.
-pub(crate) fn choose_winnable_seed(initial_seed: u64, draw_mode: DrawMode) -> u64 {
+pub(crate) fn choose_winnable_seed(initial_seed: u64, draw_mode: DrawStockConfig) -> u64 {
     let mut seed = initial_seed;
     for _ in 0..SOLVER_DEAL_RETRY_CAP {
-        match try_solve(
+        match GameState::solve_fresh_deal(
             seed,
             draw_mode,
             DEFAULT_SOLVE_MOVES_BUDGET,
@@ -826,14 +824,14 @@ fn handle_draw(
         // so we can fire flip events after they land face-up in the waste.
         // Only relevant when stock is non-empty; a recycle moves waste back to
         // stock face-down, so no flip events are needed in that case.
-        let drawn_cards: Vec<solitaire_core::card::Card> = {
+        let drawn_cards: Vec<solitaire_core::Card> = {
             let stock = game.0.stock_cards();
             if stock.is_empty() {
                 Vec::new()
             } else {
                 let draw_count = match game.0.draw_mode() {
-                    DrawMode::DrawOne => 1_usize,
+                    DrawStockConfig::DrawOne => 1_usize,
-                    DrawMode::DrawThree => 3_usize,
+                    DrawStockConfig::DrawThree => 3_usize,
                 };
                 let n = stock.len();
                 let take = n.min(draw_count);
@@ -920,7 +918,7 @@ fn handle_move(
                 changed.write(StateChangedEvent);
                 if !was_won && game.0.is_won() {
                     won.write(GameWonEvent {
-                        score: game.0.score,
+                        score: game.0.score(),
                         time_seconds: game.0.elapsed_seconds,
                     });
                     // Delete the saved state — a won game should not be resumed.
@@ -1015,7 +1013,7 @@ pub fn record_replay_on_win(
     }
 }
 
-fn pile_cards(game: &GameState, pile: &KlondikePile) -> Vec<(solitaire_core::card::Card, bool)> {
+fn pile_cards(game: &GameState, pile: &KlondikePile) -> Vec<(solitaire_core::Card, bool)> {
     match pile {
         KlondikePile::Stock => game.waste_cards(),
         _ => game.pile(*pile),
@@ -1117,7 +1115,7 @@ fn check_no_moves(
         // Only spawn the overlay if one does not already exist, and no other
         // modal scrim is currently open (global ModalScrim guard).
         if game_over_screens.is_empty() && scrims.is_empty() {
-            spawn_game_over_screen(&mut commands, game.0.score, font_res.as_deref());
+            spawn_game_over_screen(&mut commands, game.0.score(), font_res.as_deref());
         }
     }
 }
@@ -1326,7 +1324,7 @@ mod tests {
         app.insert_resource(PendingRestoredGame(None));
         // Override the system-time seed with a known value.
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new(seed, DrawMode::DrawOne);
+            GameState::new(seed, DrawStockConfig::DrawOne);
         app
     }
 
@@ -1393,7 +1391,7 @@ mod tests {
     #[test]
     fn new_game_request_reseeds() {
         let mut app = test_app(1);
-        let before: Vec<solitaire_core::card::Card> = app
+        let before: Vec<solitaire_core::Card> = app
             .world()
             .resource::<GameStateResource>()
             .0
@@ -1409,7 +1407,7 @@ mod tests {
         });
         app.update();
 
-        let after: Vec<solitaire_core::card::Card> = app
+        let after: Vec<solitaire_core::Card> = app
             .world()
             .resource::<GameStateResource>()
             .0
@@ -1542,7 +1540,7 @@ mod tests {
         app.insert_resource(GameStatePath(Some(path.clone())));
         // Override the seed so we can verify it was written.
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new(7654, DrawMode::DrawOne);
+            GameState::new(7654, DrawStockConfig::DrawOne);
 
         app.world_mut().write_message(AppExit::Success);
         app.update();
@@ -1561,7 +1559,7 @@ mod tests {
 
         let path = tmp_gs_path("new_game_delete");
         // Pre-create a saved file.
-        save_game_state_to(&path, &GameState::new(1, DrawMode::DrawOne)).unwrap();
+        save_game_state_to(&path, &GameState::new(1, DrawStockConfig::DrawOne)).unwrap();
         assert!(path.exists());
 
         let mut app = test_app(1);
@@ -1651,7 +1649,7 @@ mod tests {
 
     #[test]
     fn moving_cards_off_face_up_card_does_not_fire_card_flipped_event() {
-        use solitaire_core::card::{Card, Deck, Rank, Suit};
+        use solitaire_core::{Card, Deck, Rank, Suit};
         let mut app = test_app(1);
         // Build a tableau with two face-up cards.
         {
@@ -1695,7 +1693,7 @@ mod tests {
     fn has_legal_moves_returns_true_for_fresh_game() {
         // A fresh deal always has a non-empty stock (24 cards), so drawing
         // is always a legal move regardless of the initial face-up tableau cards.
-        let game = GameState::new(42, DrawMode::DrawOne);
+        let game = GameState::new(42, DrawStockConfig::DrawOne);
         assert!(
             has_legal_moves(&game),
             "fresh deal must contain at least one legal move"
@@ -1708,8 +1706,8 @@ mod tests {
         // Klondike (unlimited recycles), even if the drawn card cannot be
         // immediately placed. The game is only stuck when both stock AND waste
         // are exhausted and no visible card can be moved.
-        use solitaire_core::card::{Card, Deck, Rank, Suit};
+        use solitaire_core::{Card, Deck, Rank, Suit};
-        let mut game = GameState::new(1, DrawMode::DrawOne);
+        let mut game = GameState::new(1, DrawStockConfig::DrawOne);
         for foundation in [
             Foundation::Foundation1,
             Foundation::Foundation2,
@@ -1744,8 +1742,8 @@ mod tests {
 
     #[test]
     fn has_legal_moves_returns_true_when_ace_can_go_to_foundation() {
-        use solitaire_core::card::{Card, Deck, Rank, Suit};
+        use solitaire_core::{Card, Deck, Rank, Suit};
-        let mut game = GameState::new(1, DrawMode::DrawOne);
+        let mut game = GameState::new(1, DrawStockConfig::DrawOne);
 
         // Empty stock and waste so draw is NOT available.
         game.set_test_stock_cards(Vec::new());
@@ -1788,8 +1786,8 @@ mod tests {
         // If the only legal move involves a face-up card that is NOT the top
         // card of its column the previous code would return false (softlock)
         // even though the player can still move that run.
-        use solitaire_core::card::{Card, Deck, Rank, Suit};
+        use solitaire_core::{Card, Deck, Rank, Suit};
-        let mut game = GameState::new(1, DrawMode::DrawOne);
+        let mut game = GameState::new(1, DrawStockConfig::DrawOne);
 
         game.set_test_stock_cards(Vec::new());
         game.set_test_waste_cards(Vec::new());
@@ -1978,7 +1976,7 @@ mod tests {
     /// to have been a King.
     #[test]
     fn foundation_completed_event_does_not_fire_for_non_foundation_moves() {
-        use solitaire_core::card::{Card, Deck, Rank, Suit};
+        use solitaire_core::{Card, Deck, Rank, Suit};
 
         let mut app = test_app(1);
         // Reset the world: clear stock + waste so a draw isn't possible,
@@ -2187,7 +2185,7 @@ mod tests {
         assert_eq!(loaded.seed, 7654, "seed must match the live game state");
         assert_eq!(
             loaded.draw_mode,
-            DrawMode::DrawOne,
+            DrawStockConfig::DrawOne,
             "draw_mode must be captured"
         );
         assert_eq!(
@@ -2328,7 +2326,7 @@ mod tests {
             "with solver toggle off, the requested seed must be honoured exactly"
         );
         // Cross-check: the dealt tableau must match GameState::new(999) byte-for-byte.
-        let expected = GameState::new(999, DrawMode::DrawOne);
+        let expected = GameState::new(999, DrawStockConfig::DrawOne);
         for tableau in [
             Tableau::Tableau1,
             Tableau::Tableau2,
@@ -2405,7 +2403,7 @@ mod tests {
         //
         // Seed 394 was previously Unwinnable under the old DFS; now it resolves
         // as Inconclusive, so the helper must accept it immediately.
-        let chosen = choose_winnable_seed(394, DrawMode::DrawOne);
+        let chosen = choose_winnable_seed(394, DrawStockConfig::DrawOne);
         assert_eq!(
             chosen, 394,
             "seed 394 resolves as Inconclusive; choose_winnable_seed must accept it as-is"

solitaire_engine/src/home_plugin.rs

@@ -16,7 +16,7 @@
 use bevy::input::ButtonInput;
 use bevy::input::mouse::{MouseScrollUnit, MouseWheel};
 use bevy::prelude::*;
-use solitaire_core::{DrawMode, game_state::DifficultyLevel};
+use solitaire_core::{DrawStockConfig, game_state::DifficultyLevel};
 use solitaire_data::save_settings_to;
 
 use crate::challenge_plugin::CHALLENGE_UNLOCK_LEVEL;
@@ -432,7 +432,7 @@ fn build_home_context<'a>(
         zen_best: stats.map_or(0, |s| s.0.zen_best_score),
         challenge_best: stats.map_or(0, |s| s.0.challenge_best_score),
         daily_today,
-        draw_mode: settings.map(|s| s.0.draw_mode).unwrap_or(DrawMode::DrawOne),
+        draw_mode: settings.map(|s| s.0.draw_mode).unwrap_or(DrawStockConfig::DrawOne),
         font_res,
         difficulty_expanded,
         last_difficulty: settings.and_then(|s| s.0.last_difficulty),
@@ -620,9 +620,9 @@ fn handle_home_draw_mode_buttons(
         return;
     };
     let target = if want_one {
-        DrawMode::DrawOne
+        DrawStockConfig::DrawOne
     } else {
-        DrawMode::DrawThree
+        DrawStockConfig::DrawThree
     };
     if settings.0.draw_mode == target {
         return; // already in this mode — avoid a redundant respawn.
@@ -857,7 +857,7 @@ struct HomeContext<'a> {
     challenge_best: u32,
     daily_streak: u32,
     daily_today: Option<DailyToday>,
-    draw_mode: DrawMode,
+    draw_mode: DrawStockConfig,
     font_res: Option<&'a FontResource>,
     /// Whether the difficulty section header is currently expanded.
     difficulty_expanded: bool,
@@ -1038,7 +1038,7 @@ fn spawn_draw_mode_row(parent: &mut ChildSpawnerCommands, ctx: &HomeContext<'_>)
         ..default()
     };
 
-    let active_one = matches!(ctx.draw_mode, DrawMode::DrawOne);
+    let active_one = matches!(ctx.draw_mode, DrawStockConfig::DrawOne);
 
     parent
         .spawn(Node {

solitaire_engine/src/hud_plugin.rs

@@ -9,8 +9,8 @@
 use bevy::prelude::*;
 use bevy::window::WindowResized;
 use solitaire_core::{Foundation, KlondikePile, Tableau};
-use solitaire_core::card::Suit;
+use solitaire_core::Suit;
-use solitaire_core::{DrawMode, game_state::GameMode};
+use solitaire_core::{DrawStockConfig, game_state::GameMode};
 
 use crate::auto_complete_plugin::AutoCompleteState;
 #[cfg(not(target_arch = "wasm32"))]
@@ -1818,7 +1818,7 @@ fn detect_score_change(
     score_q: Query<Entity, With<HudScore>>,
     mut commands: Commands,
 ) {
-    let current = game.0.score;
+    let current = game.0.score();
     let delta = current - prev.0;
     prev.0 = current;
     if delta <= 0 {
@@ -2275,7 +2275,7 @@ fn update_hud(
             **t = if is_zen {
                 String::new()
             } else {
-                format!("Score: {}", g.score)
+                format!("Score: {}", g.score())
             };
         }
         if let Ok(mut t) = moves_q.single_mut() {
@@ -2284,8 +2284,8 @@ fn update_hud(
         if let Ok(mut t) = mode_q.single_mut() {
             **t = match g.mode {
                 GameMode::Classic => match g.draw_mode() {
-                    DrawMode::DrawOne => String::new(),
+                    DrawStockConfig::DrawOne => String::new(),
-                    DrawMode::DrawThree => "Draw 3".to_string(),
+                    DrawStockConfig::DrawThree => "Draw 3".to_string(),
                 },
                 GameMode::Zen => "ZEN".to_string(),
                 GameMode::Challenge => "CHALLENGE".to_string(),
@@ -2311,7 +2311,7 @@ fn update_hud(
 
         // --- Undo count ---
         if let Ok((mut t, mut color)) = undos_q.single_mut() {
-            let count = g.undo_count;
+            let count = g.undo_count();
             if count == 0 {
                 **t = String::new();
                 *color = TextColor(TEXT_PRIMARY);
@@ -2325,8 +2325,8 @@ fn update_hud(
 
         // --- Recycle counter (both modes, hidden until first recycle) ---
         if let Ok(mut t) = recycles_q.single_mut() {
-            **t = if g.recycle_count > 0 {
+            **t = if g.recycle_count() > 0 {
-                format!("Recycles: {}", g.recycle_count)
+                format!("Recycles: {}", g.recycle_count())
             } else {
                 String::new()
             };
@@ -2334,7 +2334,7 @@ fn update_hud(
 
         // --- Draw-cycle indicator (Draw-Three mode only) ---
         if let Ok(mut t) = draw_cycle_q.single_mut() {
-            **t = if g.is_won() || g.draw_mode() != DrawMode::DrawThree {
+            **t = if g.is_won() || g.draw_mode() != DrawStockConfig::DrawThree {
                 // Hide when not in Draw-Three or after the game is won.
                 String::new()
             } else {
@@ -2726,7 +2726,7 @@ mod tests {
     use crate::game_plugin::GamePlugin;
     use crate::table_plugin::TablePlugin;
     use chrono::Local;
-    use solitaire_core::{DrawMode, game_state::GameState};
+    use solitaire_core::{DrawStockConfig, game_state::GameState};
 
     fn headless_app() -> App {
         let mut app = App::new();
@@ -2747,7 +2747,7 @@ mod tests {
     fn update_hud_runs_after_game_mutation_without_panic() {
         let mut app = headless_app();
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new(42, DrawMode::DrawOne);
+            GameState::new(42, DrawStockConfig::DrawOne);
         app.update();
     }
 
@@ -2763,9 +2763,9 @@ mod tests {
     #[test]
     fn score_reflects_game_state() {
         let mut app = headless_app();
-        app.world_mut().resource_mut::<GameStateResource>().0.score = 750;
+        let score = app.world_mut().resource_mut::<GameStateResource>().0.force_test_score(20);
         app.update();
-        assert_eq!(read_hud_text::<HudScore>(&mut app), "Score: 750");
+        assert_eq!(read_hud_text::<HudScore>(&mut app), format!("Score: {score}"));
     }
 
     #[test]
@@ -2784,7 +2784,7 @@ mod tests {
         use solitaire_core::game_state::GameMode;
         let mut app = headless_app();
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new_with_mode(42, DrawMode::DrawThree, GameMode::Classic);
+            GameState::new_with_mode(42, DrawStockConfig::DrawThree, GameMode::Classic);
         app.update();
         assert_eq!(read_hud_text::<HudMode>(&mut app), "Draw 3");
     }
@@ -2794,8 +2794,7 @@ mod tests {
         use solitaire_core::game_state::GameMode;
         let mut app = headless_app();
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new_with_mode(42, DrawMode::DrawOne, GameMode::Zen);
+            GameState::new_with_mode(42, DrawStockConfig::DrawOne, GameMode::Zen);
-        app.world_mut().resource_mut::<GameStateResource>().0.score = 999;
         app.update();
         // Zen mode spec: "No score display" → text must be empty.
         assert_eq!(read_hud_text::<HudScore>(&mut app), "");
@@ -2916,7 +2915,7 @@ mod tests {
     fn challenge_hud_empty_when_no_daily_resource() {
         // No DailyChallengeResource inserted → HudChallenge must be empty.
         let mut app = headless_app();
-        app.world_mut().resource_mut::<GameStateResource>().0.score = 1; // force change
+        app.world_mut().resource_mut::<GameStateResource>().set_changed();
         app.update();
         assert_eq!(read_hud_text::<HudChallenge>(&mut app), "");
     }
@@ -2931,7 +2930,7 @@ mod tests {
             target_score: None,
             max_time_secs: Some(300),
         });
-        app.world_mut().resource_mut::<GameStateResource>().0.score = 1; // force change
+        app.world_mut().resource_mut::<GameStateResource>().set_changed();
         app.update();
         assert_eq!(read_hud_text::<HudChallenge>(&mut app), "Limit: 5:00");
     }
@@ -2946,7 +2945,7 @@ mod tests {
             target_score: Some(4000),
             max_time_secs: None,
         });
-        app.world_mut().resource_mut::<GameStateResource>().0.score = 1;
+        app.world_mut().resource_mut::<GameStateResource>().set_changed();
         app.update();
         assert_eq!(read_hud_text::<HudChallenge>(&mut app), "Goal: 4000 pts");
     }
@@ -2984,7 +2983,7 @@ mod tests {
         app.world_mut()
             .resource_mut::<GameStateResource>()
             .0
-            .undo_count = 3;
+            .force_test_undos(3);
         app.update();
         assert_eq!(read_hud_text::<HudUndos>(&mut app), "Undos: 3");
     }
@@ -3038,7 +3037,7 @@ mod tests {
         let mut app = headless_app();
         // Draw-One, no recycles yet — text must be empty.
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new(42, DrawMode::DrawOne);
+            GameState::new(42, DrawStockConfig::DrawOne);
         app.update();
         assert_eq!(read_hud_text::<HudRecycles>(&mut app), "");
     }
@@ -3048,7 +3047,7 @@ mod tests {
         let mut app = headless_app();
         // Draw-Three, no recycles yet — text must also be empty.
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new(42, DrawMode::DrawThree);
+            GameState::new(42, DrawStockConfig::DrawThree);
         app.update();
         assert_eq!(read_hud_text::<HudRecycles>(&mut app), "");
     }
@@ -3056,8 +3055,8 @@ mod tests {
     #[test]
     fn recycles_hud_shows_count_draw_three() {
         let mut app = headless_app();
-        let mut gs = GameState::new(42, DrawMode::DrawThree);
+        let mut gs = GameState::new(42, DrawStockConfig::DrawThree);
-        gs.recycle_count = 3;
+        gs.force_test_recycles(3);
         app.world_mut().resource_mut::<GameStateResource>().0 = gs;
         app.update();
         assert_eq!(read_hud_text::<HudRecycles>(&mut app), "Recycles: 3");
@@ -3067,8 +3066,8 @@ mod tests {
     fn recycles_hud_shows_count_draw_one() {
         let mut app = headless_app();
         // Draw-One with recycle_count > 0 must now show the counter too.
-        let mut gs = GameState::new(42, DrawMode::DrawOne);
+        let mut gs = GameState::new(42, DrawStockConfig::DrawOne);
-        gs.recycle_count = 2;
+        gs.force_test_recycles(2);
         app.world_mut().resource_mut::<GameStateResource>().0 = gs;
         app.update();
         assert_eq!(read_hud_text::<HudRecycles>(&mut app), "Recycles: 2");
@@ -3108,7 +3107,7 @@ mod tests {
         set_manual_time_step(&mut app, 0.0);
         // Initial state has score=0; bumping by 50 (the threshold)
         // is the smallest jump that triggers the floater.
-        app.world_mut().resource_mut::<GameStateResource>().0.score = 50;
+        app.world_mut().resource_mut::<GameStateResource>().0.force_test_score(50);
         app.update();
 
         // One floater should now exist.
@@ -3129,7 +3128,7 @@ mod tests {
     #[test]
     fn score_floater_despawns_after_full_lifetime() {
         let mut app = headless_app();
-        app.world_mut().resource_mut::<GameStateResource>().0.score = 100;
+        app.world_mut().resource_mut::<GameStateResource>().0.force_test_score(50);
         app.update();
         assert_eq!(count_with::<ScoreFloater>(&mut app), 1);
 
@@ -3155,7 +3154,7 @@ mod tests {
         let mut app = headless_app();
         // +5 mirrors a single tableau-to-foundation move; well below
         // the 50-point threshold so the floater path stays dormant.
-        app.world_mut().resource_mut::<GameStateResource>().0.score = 5;
+        app.world_mut().resource_mut::<GameStateResource>().0.force_test_score(5);
         app.update();
         assert_eq!(
             count_with::<ScoreFloater>(&mut app),
@@ -3231,7 +3230,7 @@ mod tests {
             ..Settings::default()
         }));
         // +100 would normally create both a ScorePulse and a ScoreFloater.
-        app.world_mut().resource_mut::<GameStateResource>().0.score = 100;
+        app.world_mut().resource_mut::<GameStateResource>().0.force_test_score(50);
         app.update();
         assert_eq!(
             count_with::<ScorePulse>(&mut app),

solitaire_engine/src/input_plugin.rs

@@ -27,13 +27,15 @@ use bevy::window::PrimaryWindow;
 #[cfg(not(target_os = "android"))]
 use bevy::window::{MonitorSelection, WindowMode};
 use solitaire_core::{Foundation, KlondikeInstruction, KlondikePile, Tableau};
-use solitaire_core::card::{Card, Suit};
+use solitaire_core::{Card, Suit};
 use solitaire_core::game_state::GameState;
 
 use crate::auto_complete_plugin::AutoCompleteState;
 use crate::card_animation::tuning::AnimationTuning;
 use crate::card_animation::{CardAnimation, MotionCurve};
-use crate::card_plugin::{CardEntity, HintHighlight, HintHighlightTimer, STACK_FAN_FRAC};
+use crate::card_plugin::{
+    CardEntity, CardEntityIndex, HintHighlight, HintHighlightTimer, STACK_FAN_FRAC,
+};
 use crate::challenge_plugin::CHALLENGE_UNLOCK_LEVEL;
 use crate::events::{
     DrawRequestEvent, ForfeitRequestEvent, HintVisualEvent, InfoToastEvent, MoveRejectedEvent,
@@ -52,7 +54,7 @@ use crate::settings_plugin::SettingsResource;
 use crate::time_attack_plugin::TimeAttackResource;
 use crate::touch_selection_plugin::TouchSelectionState;
 use crate::ui_theme::{MOTION_DRAG_REJECT_SECS, STATE_SUCCESS, STATE_WARNING};
-use solitaire_core::DrawMode;
+use solitaire_core::DrawStockConfig;
 
 /// System-set labels used to anchor external systems relative to the touch
 /// drag pipeline without duplicating the internal chain ordering.
@@ -93,8 +95,8 @@ pub struct HintSolverConfig {
 impl Default for HintSolverConfig {
     fn default() -> Self {
         Self {
-            moves_budget: solitaire_data::solver::DEFAULT_SOLVE_MOVES_BUDGET,
+            moves_budget: solitaire_core::DEFAULT_SOLVE_MOVES_BUDGET,
-            states_budget: solitaire_data::solver::DEFAULT_SOLVE_STATES_BUDGET,
+            states_budget: solitaire_core::DEFAULT_SOLVE_STATES_BUDGET,
         }
     }
 }
@@ -121,6 +123,10 @@ impl Plugin for InputPlugin {
             .init_resource::<HintSolverConfig>()
             .init_resource::<crate::pending_hint::PendingHintTask>()
             .init_resource::<GameInputConsumedResource>()
+            // The drag systems resolve cards via `CardEntityIndex`; `CardPlugin`
+            // owns and rebuilds it, but init here too so `InputPlugin` is
+            // self-sufficient in tests (idempotent if already registered).
+            .init_resource::<CardEntityIndex>()
             .add_message::<StartZenRequestEvent>()
             .add_message::<InfoToastEvent>()
             .add_message::<ForfeitRequestEvent>()
@@ -674,6 +680,7 @@ fn follow_drag(
     layout: Option<Res<LayoutResource>>,
     tuning: Res<AnimationTuning>,
     mut card_transforms: Query<(&CardEntity, &mut Transform, &mut Sprite)>,
+    card_index: Res<CardEntityIndex>,
 ) {
     // Skip if idle or if a touch drag is running.
     if drag.is_idle() || drag.active_touch_id.is_some() {
@@ -704,9 +711,8 @@ fn follow_drag(
         // Elevate cards: push to DRAG_Z and dim slightly so the board
         // beneath stays readable.
         for (i, card) in drag.cards.iter().enumerate() {
-            if let Some((_, mut transform, mut sprite)) = card_transforms
+            if let Some(entity) = card_index.get(card)
-                .iter_mut()
+                && let Ok((_, mut transform, mut sprite)) = card_transforms.get_mut(entity)
-                .find(|(ce, _, _)| ce.card == *card)
             {
                 transform.translation.z = dragged_card_z(i);
                 sprite.color.set_alpha(0.85);
@@ -719,9 +725,8 @@ fn follow_drag(
     let fan = -layout.0.card_size.y * layout.0.tableau_fan_frac;
 
     for (i, card) in drag.cards.iter().enumerate() {
-        if let Some((_, mut transform, _)) = card_transforms
+        if let Some(entity) = card_index.get(card)
-            .iter_mut()
+            && let Ok((_, mut transform, _)) = card_transforms.get_mut(entity)
-            .find(|(ce, _, _)| ce.card == *card)
         {
             transform.translation.x = bottom_pos.x;
             transform.translation.y = bottom_pos.y + fan * i as f32;
@@ -743,6 +748,7 @@ fn end_drag(
     mut changed: MessageWriter<StateChangedEvent>,
     mut commands: Commands,
     card_entities: Query<(Entity, &CardEntity, &Transform)>,
+    card_index: Res<CardEntityIndex>,
 ) {
     if paused.is_some_and(|p| p.0) {
         drag.clear();
@@ -830,9 +836,8 @@ fn end_drag(
                         continue;
                     };
                     let target_pos = card_position(&game.0, &layout.0, &origin, stack_index);
-                    if let Some((entity, _, transform)) = card_entities
+                    if let Some(entity) = card_index.get(card)
-                        .iter()
+                        && let Ok((_, _, transform)) = card_entities.get(entity)
-                        .find(|(_, ce, _)| ce.card == *card)
                     {
                         let drag_pos = transform.translation.truncate();
                         let drag_z = transform.translation.z;
@@ -930,6 +935,7 @@ fn touch_follow_drag(
     layout: Option<Res<LayoutResource>>,
     tuning: Res<AnimationTuning>,
     mut card_transforms: Query<(&CardEntity, &mut Transform, &mut Sprite)>,
+    card_index: Res<CardEntityIndex>,
 ) {
     let Some(active_id) = drag.active_touch_id else {
         return; // Mouse drag or idle.
@@ -957,9 +963,8 @@ fn touch_follow_drag(
         drag.committed = true;
 
         for (i, card) in drag.cards.iter().enumerate() {
-            if let Some((_, mut transform, mut sprite)) = card_transforms
+            if let Some(entity) = card_index.get(card)
-                .iter_mut()
+                && let Ok((_, mut transform, mut sprite)) = card_transforms.get_mut(entity)
-                .find(|(ce, _, _)| ce.card == *card)
             {
                 transform.translation.z = dragged_card_z(i);
                 sprite.color.set_alpha(0.85);
@@ -971,9 +976,8 @@ fn touch_follow_drag(
     let fan = -layout.0.card_size.y * layout.0.tableau_fan_frac;
 
     for (i, card) in drag.cards.iter().enumerate() {
-        if let Some((_, mut transform, _)) = card_transforms
+        if let Some(entity) = card_index.get(card)
-            .iter_mut()
+            && let Ok((_, mut transform, _)) = card_transforms.get_mut(entity)
-            .find(|(ce, _, _)| ce.card == *card)
         {
             transform.translation.x = bottom_pos.x;
             transform.translation.y = bottom_pos.y + fan * i as f32;
@@ -998,6 +1002,7 @@ fn touch_end_drag(
     mut changed: MessageWriter<StateChangedEvent>,
     mut commands: Commands,
     card_entities: Query<(Entity, &CardEntity, &Transform)>,
+    card_index: Res<CardEntityIndex>,
 ) {
     let Some(active_id) = drag.active_touch_id else {
         return; // Mouse drag or idle.
@@ -1070,9 +1075,8 @@ fn touch_end_drag(
                             continue;
                         };
                         let target_pos = card_position(&game.0, &layout.0, &origin, stack_index);
-                        if let Some((entity, _, transform)) = card_entities
+                        if let Some(entity) = card_index.get(card)
-                            .iter()
+                            && let Ok((_, _, transform)) = card_entities.get(entity)
-                            .find(|(_, ce, _)| ce.card == *card)
                         {
                             let drag_pos = transform.translation.truncate();
                             let drag_z = transform.translation.z;
@@ -1169,7 +1173,7 @@ fn card_position(
             y_offset -= layout.card_size.y * step;
         }
         Vec2::new(base.x, base.y + y_offset)
-    } else if matches!(pile, KlondikePile::Stock) && game.draw_mode() == DrawMode::DrawThree {
+    } else if matches!(pile, KlondikePile::Stock) && game.draw_mode() == DrawStockConfig::DrawThree {
         // In Draw-Three mode the top 3 waste cards are fanned in X to match
         // card_plugin::card_positions(). Hit-testing must use the same offsets
         // so clicking the visually rightmost (top) card actually registers.
@@ -1826,7 +1830,7 @@ mod tests {
     use super::*;
     use crate::layout::compute_layout;
     use solitaire_core::{Foundation, Tableau};
-    use solitaire_core::{DrawMode, game_state::GameState};
+    use solitaire_core::{DrawStockConfig, game_state::GameState};
 
     fn clear_test_piles(game: &mut GameState) {
         game.set_test_stock_cards(Vec::new());
@@ -1894,7 +1898,7 @@ mod tests {
 
     #[test]
     fn find_draggable_picks_top_of_tableau() {
-        let game = GameState::new(42, DrawMode::DrawOne);
+        let game = GameState::new(42, DrawStockConfig::DrawOne);
         let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0, true);
 
         // In tableau 6, the visually topmost card is the last (face-up) one.
@@ -1908,7 +1912,7 @@ mod tests {
 
     #[test]
     fn find_draggable_skips_face_down_cards() {
-        let game = GameState::new(42, DrawMode::DrawOne);
+        let game = GameState::new(42, DrawStockConfig::DrawOne);
         let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0, true);
 
         // Tableau 6 has 7 cards: 6 face-down (indices 0..5) + 1 face-up at
@@ -1930,7 +1934,7 @@ mod tests {
         // at 0.12 — so for any column with face-down cards above the
         // face-up bottom card, clicking the visible card face missed the
         // hit-test box and only the bottom strip of the card responded.
-        let game = GameState::new(42, DrawMode::DrawOne);
+        let game = GameState::new(42, DrawStockConfig::DrawOne);
         let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0, true);
 
         // Tableau 6 starts with 6 face-down + 1 face-up. The face-up card
@@ -1948,9 +1952,9 @@ mod tests {
     #[test]
     fn find_draggable_returns_run_when_picking_mid_stack() {
         // Manually construct a tableau with three face-up cards all stacked.
-        let mut game = GameState::new(1, DrawMode::DrawOne);
+        let mut game = GameState::new(1, DrawStockConfig::DrawOne);
-        use solitaire_core::card::Deck as D;
+        use solitaire_core::Deck as D;
-        use solitaire_core::card::{Card, Rank, Suit};
+        use solitaire_core::{Card, Rank, Suit};
         let king = Card::new(D::Deck1, Suit::Spades, Rank::King);
         let queen = Card::new(D::Deck1, Suit::Hearts, Rank::Queen);
         let jack = Card::new(D::Deck1, Suit::Clubs, Rank::Jack);
@@ -1975,9 +1979,9 @@ mod tests {
 
     #[test]
     fn find_draggable_skips_non_top_waste_card() {
-        let mut game = GameState::new(1, DrawMode::DrawOne);
+        let mut game = GameState::new(1, DrawStockConfig::DrawOne);
-        use solitaire_core::card::Deck as D;
+        use solitaire_core::Deck as D;
-        use solitaire_core::card::{Card, Rank, Suit};
+        use solitaire_core::{Card, Rank, Suit};
         let two_spades = Card::new(D::Deck1, Suit::Spades, Rank::Two);
         let three_hearts = Card::new(D::Deck1, Suit::Hearts, Rank::Three);
         game.set_test_waste_cards(vec![two_spades, three_hearts.clone()]);
@@ -1994,7 +1998,7 @@ mod tests {
 
     #[test]
     fn find_drop_target_hits_empty_tableau_pile_marker() {
-        let game = GameState::new(42, DrawMode::DrawOne);
+        let game = GameState::new(42, DrawStockConfig::DrawOne);
         let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0, true);
         // Move all cards out of tableau 0 so its marker is the only drop area.
         let mut game = game;
@@ -2011,7 +2015,7 @@ mod tests {
 
     #[test]
     fn find_drop_target_returns_none_for_origin() {
-        let game = GameState::new(42, DrawMode::DrawOne);
+        let game = GameState::new(42, DrawStockConfig::DrawOne);
         let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0, true);
         let pos = layout.pile_positions[&KlondikePile::Tableau(Tableau::Tableau4)];
         let target = find_drop_target(
@@ -2025,7 +2029,7 @@ mod tests {
 
     #[test]
     fn pile_drop_rect_extends_for_tableau_with_cards() {
-        let game = GameState::new(42, DrawMode::DrawOne);
+        let game = GameState::new(42, DrawStockConfig::DrawOne);
         let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0, true);
         // Tableau 6 has 7 cards.
         let (_, size) = pile_drop_rect(&KlondikePile::Tableau(Tableau::Tableau7), &layout, &game);
@@ -2040,10 +2044,10 @@ mod tests {
 
     #[test]
     fn find_draggable_draw_three_waste_top_card_hit_at_fanned_position() {
-        use solitaire_core::card::Deck as D;
+        use solitaire_core::Deck as D;
-        use solitaire_core::card::{Card, Rank, Suit};
+        use solitaire_core::{Card, Rank, Suit};
-        use solitaire_core::{DrawMode, game_state::GameMode};
+        use solitaire_core::{DrawStockConfig, game_state::GameMode};
-        let mut game = GameState::new_with_mode(1, DrawMode::DrawThree, GameMode::Classic);
+        let mut game = GameState::new_with_mode(1, DrawStockConfig::DrawThree, GameMode::Classic);
         // Three waste cards; top (four_clubs) is rightmost in the fan.
         let two_spades = Card::new(D::Deck1, Suit::Spades, Rank::Two);
         let three_hearts = Card::new(D::Deck1, Suit::Hearts, Rank::Three);
@@ -2068,7 +2072,7 @@ mod tests {
 
     #[test]
     fn find_draggable_returns_none_for_click_on_empty_pile() {
-        let mut game = GameState::new(42, DrawMode::DrawOne);
+        let mut game = GameState::new(42, DrawStockConfig::DrawOne);
         let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0, true);
         // Clear tableau 0 so it's an empty slot.
         game.set_test_tableau_cards(Tableau::Tableau1, Vec::new());
@@ -2082,7 +2086,7 @@ mod tests {
 
     #[test]
     fn pile_drop_rect_is_card_sized_for_non_tableau() {
-        let game = GameState::new(42, DrawMode::DrawOne);
+        let game = GameState::new(42, DrawStockConfig::DrawOne);
         let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0, true);
         for pile in [
             KlondikePile::Stock,
@@ -2099,9 +2103,9 @@ mod tests {
 
     #[test]
     fn best_destination_returns_none_when_no_legal_move() {
-        use solitaire_core::card::Deck as D;
+        use solitaire_core::Deck as D;
-        use solitaire_core::card::{Card, Rank, Suit};
+        use solitaire_core::{Card, Rank, Suit};
-        let mut game = GameState::new(1, DrawMode::DrawOne);
+        let mut game = GameState::new(1, DrawStockConfig::DrawOne);
 
         // Clear everything except one card that has nowhere to go.
         clear_test_piles(&mut game);
@@ -2117,9 +2121,9 @@ mod tests {
 
     #[test]
     fn best_tableau_destination_for_stack_skips_source_pile() {
-        use solitaire_core::card::Deck as D;
+        use solitaire_core::Deck as D;
-        use solitaire_core::card::{Card, Rank, Suit};
+        use solitaire_core::{Card, Rank, Suit};
-        let mut game = GameState::new(1, DrawMode::DrawOne);
+        let mut game = GameState::new(1, DrawStockConfig::DrawOne);
 
         clear_test_piles(&mut game);
 
@@ -2143,9 +2147,9 @@ mod tests {
 
     #[test]
     fn best_tableau_destination_for_stack_returns_none_when_no_legal_move() {
-        use solitaire_core::card::Deck as D;
+        use solitaire_core::Deck as D;
-        use solitaire_core::card::{Card, Rank, Suit};
+        use solitaire_core::{Card, Rank, Suit};
-        let mut game = GameState::new(1, DrawMode::DrawOne);
+        let mut game = GameState::new(1, DrawStockConfig::DrawOne);
 
         clear_test_piles(&mut game);
 
@@ -2172,9 +2176,9 @@ mod tests {
 
     #[test]
     fn find_hint_finds_ace_to_foundation() {
-        use solitaire_core::card::Deck as D;
+        use solitaire_core::Deck as D;
-        use solitaire_core::card::{Card, Rank, Suit};
+        use solitaire_core::{Card, Rank, Suit};
-        let mut game = GameState::new(1, DrawMode::DrawOne);
+        let mut game = GameState::new(1, DrawStockConfig::DrawOne);
 
         // Place Ace of Clubs on top of tableau 0.
         clear_test_piles(&mut game);
@@ -2216,9 +2220,9 @@ mod tests {
     /// are no other moves and the stock is non-empty.
     #[test]
     fn all_hints_suggests_draw_when_no_moves_and_stock_nonempty() {
-        use solitaire_core::card::Deck as D;
+        use solitaire_core::Deck as D;
-        use solitaire_core::card::{Card, Rank, Suit};
+        use solitaire_core::{Card, Rank, Suit};
-        let mut game = GameState::new(1, DrawMode::DrawOne);
+        let mut game = GameState::new(1, DrawStockConfig::DrawOne);
 
         // Remove all foundation, tableau, and waste cards so no pile-to-pile
         // move exists. Leave one card in the stock.
@@ -2269,8 +2273,8 @@ mod tests {
     /// gets a CardAnimation" — same coverage, new component.
     #[test]
     fn rejected_drag_inserts_card_animation_on_each_dragged_card() {
-        use solitaire_core::card::Deck as D;
+        use solitaire_core::Deck as D;
-        use solitaire_core::card::{Card, Rank, Suit};
+        use solitaire_core::{Card, Rank, Suit};
         // Simulate a stack drag of two cards.
         let dragged_cards: Vec<Card> = vec![
             Card::new(D::Deck1, Suit::Hearts, Rank::King),
@@ -2427,7 +2431,7 @@ mod tests {
         app.insert_resource(crate::layout::LayoutResource(
             crate::layout::compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0, true),
         ));
-        app.insert_resource(GameStateResource(GameState::new(42, DrawMode::DrawOne)));
+        app.insert_resource(GameStateResource(GameState::new(42, DrawStockConfig::DrawOne)));
         app.add_systems(Update, handle_keyboard_hint);
 
         // Simulate the H key being pressed this frame.

solitaire_engine/src/pause_plugin.rs

@@ -21,7 +21,7 @@
 //! active opens the overlay as normal.
 
 use bevy::prelude::*;
-use solitaire_core::DrawMode;
+use solitaire_core::DrawStockConfig;
 use solitaire_data::save_game_state_to;
 
 use crate::events::{
@@ -86,10 +86,10 @@ struct ForfeitConfirmButton;
 /// Returns the human-readable label for a draw mode.
 ///
 /// Used on the pause overlay draw-mode toggle button.
-pub fn draw_mode_label(mode: DrawMode) -> &'static str {
+pub fn draw_mode_label(mode: DrawStockConfig) -> &'static str {
     match mode {
-        DrawMode::DrawOne => "Draw 1",
+        DrawStockConfig::DrawOne => "Draw 1",
-        DrawMode::DrawThree => "Draw 3",
+        DrawStockConfig::DrawThree => "Draw 3",
     }
 }
 
@@ -273,9 +273,9 @@ fn handle_pause_draw_buttons(
     }
     let Some(mut settings) = settings else { return };
     let new_mode = if pressed_one {
-        DrawMode::DrawOne
+        DrawStockConfig::DrawOne
     } else {
-        DrawMode::DrawThree
+        DrawStockConfig::DrawThree
     };
     if settings.0.draw_mode == new_mode {
         return;
@@ -477,7 +477,7 @@ fn spawn_pause_screen(
     commands: &mut Commands,
     level: Option<u32>,
     streak: Option<u32>,
-    draw_mode: Option<DrawMode>,
+    draw_mode: Option<DrawStockConfig>,
     font_res: Option<&FontResource>,
 ) {
     spawn_modal(commands, PauseScreen, ui_theme::Z_PAUSE, |card| {
@@ -516,7 +516,7 @@ fn spawn_pause_screen(
 /// `Tertiary` (recessed), giving an obvious selection state at a glance.
 fn spawn_draw_mode_row(
     parent: &mut ChildSpawnerCommands,
-    mode: DrawMode,
+    mode: DrawStockConfig,
     font_res: Option<&FontResource>,
 ) {
     let label_font = TextFont {
@@ -530,8 +530,8 @@ fn spawn_draw_mode_row(
         ..default()
     };
     let (one_variant, three_variant) = match mode {
-        DrawMode::DrawOne => (ButtonVariant::Secondary, ButtonVariant::Tertiary),
+        DrawStockConfig::DrawOne => (ButtonVariant::Secondary, ButtonVariant::Tertiary),
-        DrawMode::DrawThree => (ButtonVariant::Tertiary, ButtonVariant::Secondary),
+        DrawStockConfig::DrawThree => (ButtonVariant::Tertiary, ButtonVariant::Secondary),
     };
     parent
         .spawn(Node {
@@ -800,20 +800,20 @@ mod tests {
 
     #[test]
     fn draw_mode_label_draw_one() {
-        assert_eq!(draw_mode_label(DrawMode::DrawOne), "Draw 1");
+        assert_eq!(draw_mode_label(DrawStockConfig::DrawOne), "Draw 1");
     }
 
     #[test]
     fn draw_mode_label_draw_three() {
-        assert_eq!(draw_mode_label(DrawMode::DrawThree), "Draw 3");
+        assert_eq!(draw_mode_label(DrawStockConfig::DrawThree), "Draw 3");
     }
 
     /// Both variants are covered so the match is exhaustive — this test would
-    /// fail to compile if a new DrawMode variant were added without updating
+    /// fail to compile if a new DrawStockConfig variant were added without updating
     /// `draw_mode_label`.
     #[test]
     fn draw_mode_label_covers_all_variants() {
-        for mode in [DrawMode::DrawOne, DrawMode::DrawThree] {
+        for mode in [DrawStockConfig::DrawOne, DrawStockConfig::DrawThree] {
             let label = draw_mode_label(mode);
             assert!(
                 !label.is_empty(),
@@ -842,7 +842,7 @@ mod tests {
         app.world_mut()
             .resource_mut::<SettingsResource>()
             .0
-            .draw_mode = DrawMode::DrawOne;
+            .draw_mode = DrawStockConfig::DrawOne;
 
         // Set paused so handle_pause_draw_toggle acts.
         app.world_mut().resource_mut::<PausedResource>().0 = true;
@@ -856,7 +856,7 @@ mod tests {
         let mode = &app.world().resource::<SettingsResource>().0.draw_mode;
         assert_eq!(
             *mode,
-            DrawMode::DrawThree,
+            DrawStockConfig::DrawThree,
             "pressing Draw 3 must set mode to DrawThree"
         );
 
@@ -869,7 +869,7 @@ mod tests {
         let mode2 = &app.world().resource::<SettingsResource>().0.draw_mode;
         assert_eq!(
             *mode2,
-            DrawMode::DrawOne,
+            DrawStockConfig::DrawOne,
             "pressing Draw 1 must set mode to DrawOne"
         );
 
@@ -965,11 +965,11 @@ mod tests {
     /// Provides a fresh `GameStateResource` (not won) so the modal can
     /// open. `move_count` doesn't matter — the gate is just `!is_won`.
     fn forfeit_app() -> App {
-        use solitaire_core::{DrawMode, game_state::GameState};
+        use solitaire_core::{DrawStockConfig, game_state::GameState};
         let mut app = App::new();
         app.add_plugins(MinimalPlugins).add_plugins(PausePlugin);
         app.init_resource::<ButtonInput<KeyCode>>();
-        app.insert_resource(GameStateResource(GameState::new(1, DrawMode::DrawOne)));
+        app.insert_resource(GameStateResource(GameState::new(1, DrawStockConfig::DrawOne)));
         app.update();
         app
     }
@@ -1020,11 +1020,11 @@ mod tests {
     /// hotkey was received but is currently a no-op.
     #[test]
     fn forfeit_request_emits_toast_and_skips_modal_when_game_is_won() {
-        use solitaire_core::{DrawMode, game_state::GameState};
+        use solitaire_core::{DrawStockConfig, game_state::GameState};
         let mut app = App::new();
         app.add_plugins(MinimalPlugins).add_plugins(PausePlugin);
         app.init_resource::<ButtonInput<KeyCode>>();
-        let mut game = GameState::new(1, DrawMode::DrawOne);
+        let mut game = GameState::new(1, DrawStockConfig::DrawOne);
         game.set_test_won(true);
         app.insert_resource(GameStateResource(game));
         app.update();

solitaire_engine/src/pending_hint.rs

@@ -26,7 +26,6 @@ use bevy::prelude::*;
 use bevy::tasks::{AsyncComputeTaskPool, Task, futures_lite::future};
 use solitaire_core::KlondikeInstruction;
 use solitaire_core::game_state::GameState;
-use solitaire_data::solver::try_solve_from_state;
 
 use crate::card_plugin::CardEntity;
 use crate::events::{HintVisualEvent, InfoToastEvent, StateChangedEvent};
@@ -66,7 +65,7 @@ impl PendingHintTask {
             // Winnable (`Ok(Some)`) carries the first move on a winning path;
             // unwinnable (`Ok(None)`) and inconclusive (`Err`) both fall back
             // to the live-state heuristic so H always produces feedback.
-            match try_solve_from_state(&state, moves_budget, states_budget) {
+            match state.solve_first_move(moves_budget, states_budget) {
                 Ok(Some(first_move)) => HintTaskOutput::SolverMove(first_move),
                 Ok(None) | Err(_) => HintTaskOutput::NeedsHeuristic,
             }
@@ -180,8 +179,8 @@ mod tests {
     use crate::events::HintVisualEvent;
     use crate::input_plugin::HintSolverConfig;
     use solitaire_core::{Foundation, KlondikePile, Tableau};
-    use solitaire_core::card::{Card, Deck, Rank, Suit};
+    use solitaire_core::{Card, Deck, Rank, Suit};
-    use solitaire_core::{DrawMode, game_state::GameState};
+    use solitaire_core::{DrawStockConfig, game_state::GameState};
 
     /// Build a minimal Bevy app exercising only the polling system
     /// and the resources/messages it touches.
@@ -210,7 +209,7 @@ mod tests {
     /// foundations hold A..Q for each suit, four Kings sit on
     /// tableau columns 0..3, stock and waste empty.
     fn near_finished_state() -> GameState {
-        let mut game = GameState::new(1, DrawMode::DrawOne);
+        let mut game = GameState::new(1, DrawStockConfig::DrawOne);
         game.set_test_stock_cards(Vec::new());
         game.set_test_waste_cards(Vec::new());
         for foundation in [

solitaire_engine/src/play_by_seed_plugin.rs

@@ -11,7 +11,7 @@
 //! 3. `handle_text_input` appends decimal digits / handles Backspace while
 //!    the modal is open, updating [`SeedInputBuffer`] each frame.
 //! 4. `tick_debounce_and_spawn_solver_task` waits for 12 frames (~200 ms at
-//!    60 Hz) of no input before spawning a [`try_solve`] task on
+//!    60 Hz) of no input before spawning a [`GameState::solve_fresh_deal`] task on
 //!    [`AsyncComputeTaskPool`]. Any fresh keypress drops the in-flight task
 //!    by resetting the resource.
 //! 5. `poll_solver_task` polls the in-flight task each frame and updates the
@@ -23,10 +23,9 @@
 use bevy::input::ButtonInput;
 use bevy::prelude::*;
 use bevy::tasks::{AsyncComputeTaskPool, Task, futures_lite::future};
-use solitaire_core::DrawMode;
+use solitaire_core::DrawStockConfig;
-use solitaire_data::solver::{
+use solitaire_core::game_state::GameState;
-    DEFAULT_SOLVE_MOVES_BUDGET, DEFAULT_SOLVE_STATES_BUDGET, SolveOutcome, try_solve,
+use solitaire_core::{DEFAULT_SOLVE_MOVES_BUDGET, DEFAULT_SOLVE_STATES_BUDGET, SolveOutcome};
-};
 
 use crate::events::{NewGameRequestEvent, StartPlayBySeedRequestEvent};
 use crate::font_plugin::FontResource;
@@ -341,9 +340,9 @@ fn tick_debounce_and_spawn_solver_task(
 
     let draw_mode = settings
         .as_ref()
-        .map_or(DrawMode::DrawOne, |s| s.0.draw_mode);
+        .map_or(DrawStockConfig::DrawOne, |s| s.0.draw_mode);
     let task = AsyncComputeTaskPool::get().spawn(async move {
-        try_solve(
+        GameState::solve_fresh_deal(
             seed,
             draw_mode,
             DEFAULT_SOLVE_MOVES_BUDGET,

solitaire_engine/src/progress_plugin.rs

@@ -88,7 +88,7 @@ fn award_xp_on_win(
     mut progress: ResMut<ProgressResource>,
 ) {
     for ev in wins.read() {
-        let used_undo = game.0.undo_count > 0;
+        let used_undo = game.0.undo_count() > 0;
         let amount = xp_for_win(ev.time_seconds, used_undo);
         let prev_level = progress.0.add_xp(amount);
         xp_awarded.write(XpAwardedEvent { amount });
@@ -151,7 +151,7 @@ mod tests {
         app.world_mut()
             .resource_mut::<GameStateResource>()
             .0
-            .undo_count = 1;
+            .force_test_undos(1);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,

solitaire_engine/src/radial_menu.rs

@@ -48,7 +48,7 @@ use bevy::math::Vec2;
 use bevy::prelude::*;
 use bevy::window::PrimaryWindow;
 use solitaire_core::{Foundation, KlondikePile, Tableau};
-use solitaire_core::card::Card;
+use solitaire_core::Card;
 use solitaire_core::game_state::GameState;
 
 use crate::card_plugin::TABLEAU_FACEDOWN_FAN_FRAC;
@@ -113,9 +113,9 @@ pub enum RightClickRadialState {
         /// radial is built around single-card foundation/tableau
         /// shortcuts and that matches the right-click highlight set).
         count: usize,
-        /// Card ids that would be moved (bottom-to-top order). Length
+        /// Cards that would be moved (bottom-to-top order). Length
         /// always equals `count`. Currently always one element.
-        cards: Vec<u32>,
+        cards: Vec<Card>,
         /// Pre-computed `(destination, icon_anchor_world_pos)` pairs.
         ///
         /// Anchors are evenly spaced around a ring of radius
@@ -359,7 +359,6 @@ fn pile_cards(game: &GameState, pile: &KlondikePile) -> Vec<(Card, bool)> {
     }
 }
 
-use solitaire_core::card::card_to_id;
 
 const fn foundations() -> [Foundation; 4] {
     [
@@ -500,7 +499,7 @@ fn radial_open_on_right_click(
     *state = RightClickRadialState::Active {
         source_pile,
         count: 1,
-        cards: vec![card_to_id(&card)],
+        cards: vec![card.clone()],
         legal_destinations,
         centre: world,
         hovered_index: None,
@@ -573,7 +572,7 @@ fn radial_open_on_long_press(
     *state = RightClickRadialState::Active {
         source_pile,
         count: 1,
-        cards: vec![card_to_id(&card)],
+        cards: vec![card.clone()],
         legal_destinations,
         centre: world,
         hovered_index: None,
@@ -796,8 +795,8 @@ mod tests {
     use super::*;
     use crate::layout::compute_layout;
     use bevy::ecs::message::Messages;
-    use solitaire_core::card::{Card as CoreCard, Deck, Rank, Suit};
+    use solitaire_core::{Card as CoreCard, Deck, Rank, Suit};
-    use solitaire_core::{DrawMode, game_state::GameState};
+    use solitaire_core::{DrawStockConfig, game_state::GameState};
 
     /// Build a minimal Bevy app wired with `RadialMenuPlugin` and the
     /// resources / messages it depends on. No window, no camera — the
@@ -820,7 +819,7 @@ mod tests {
     /// destination — Foundation(0) — under the standard rules
     /// (`can_place_on_foundation` accepts the Ace on an empty foundation).
     fn ace_only_state() -> GameState {
-        let mut g = GameState::new(0, DrawMode::DrawOne);
+        let mut g = GameState::new(0, DrawStockConfig::DrawOne);
         // Wipe everything.
         g.set_test_stock_cards(Vec::new());
         g.set_test_waste_cards(Vec::new());
@@ -854,7 +853,7 @@ mod tests {
     /// Place a face-down King on Tableau(0). `find_top_face_up_card_at`
     /// must skip it.
     fn face_down_only_state() -> GameState {
-        let mut g = GameState::new(0, DrawMode::DrawOne);
+        let mut g = GameState::new(0, DrawStockConfig::DrawOne);
         g.set_test_stock_cards(Vec::new());
         g.set_test_waste_cards(Vec::new());
         for foundation in [

solitaire_engine/src/replay_overlay/format.rs

@@ -1,7 +1,7 @@
 use super::ReplayPlaybackState;
 use chrono::Datelike;
 use solitaire_core::{Foundation, KlondikePile, Tableau};
-use solitaire_core::card::{Card, Rank, Suit};
+use solitaire_core::{Card, Rank, Suit};
 use solitaire_core::game_state::GameState;
 use solitaire_core::klondike_adapter::SavedKlondikePile;
 use solitaire_data::ReplayMove;

solitaire_engine/src/replay_overlay/tests.rs

@@ -1,8 +1,8 @@
 use super::*;
 use chrono::NaiveDate;
 use solitaire_core::{Foundation, KlondikePile, Tableau};
-use solitaire_core::card::{Rank, Suit};
+use solitaire_core::{Rank, Suit};
-use solitaire_core::{DrawMode, game_state::GameMode};
+use solitaire_core::{DrawStockConfig, game_state::GameMode};
 use solitaire_core::klondike_adapter::{SavedKlondikePile, SavedTableau};
 use solitaire_data::{Replay, ReplayMove};
 
@@ -13,7 +13,7 @@ use solitaire_data::{Replay, ReplayMove};
 fn synthetic_replay(move_count: usize) -> Replay {
     Replay::new(
         42,
-        DrawMode::DrawOne,
+        DrawStockConfig::DrawOne,
         GameMode::Classic,
         120,
         1_000,
@@ -2314,7 +2314,7 @@ fn format_suit_glyph_all_suits() {
 fn format_foundations_row_empty_board() {
     let game = solitaire_core::game_state::GameState::new_with_mode(
         42,
-        solitaire_core::DrawMode::DrawOne,
+        solitaire_core::DrawStockConfig::DrawOne,
         solitaire_core::game_state::GameMode::Classic,
     );
     assert_eq!(format_foundations_row(&game), "F: -- -- -- --");
@@ -2326,7 +2326,7 @@ fn format_foundations_row_empty_board() {
 fn format_stock_waste_row_initial_state() {
     let game = solitaire_core::game_state::GameState::new_with_mode(
         42,
-        solitaire_core::DrawMode::DrawOne,
+        solitaire_core::DrawStockConfig::DrawOne,
         solitaire_core::game_state::GameMode::Classic,
     );
     let text = format_stock_waste_row(&game);

solitaire_engine/src/replay_playback.rs

@@ -556,7 +556,7 @@ mod tests {
     use bevy::time::TimeUpdateStrategy;
     use chrono::NaiveDate;
     use solitaire_core::{KlondikePile, Tableau};
-    use solitaire_core::{DrawMode, game_state::GameMode};
+    use solitaire_core::{DrawStockConfig, game_state::GameMode};
     use solitaire_core::klondike_adapter::{SavedKlondikePile, SavedTableau};
     use std::time::Duration;
 
@@ -598,7 +598,7 @@ mod tests {
     fn sample_replay_three_moves() -> Replay {
         Replay::new(
             12345,
-            DrawMode::DrawOne,
+            DrawStockConfig::DrawOne,
             GameMode::Classic,
             60,
             500,
@@ -771,7 +771,7 @@ mod tests {
         let mut app = headless_app();
         let one_move = Replay::new(
             42,
-            DrawMode::DrawOne,
+            DrawStockConfig::DrawOne,
             GameMode::Classic,
             10,
             100,
@@ -880,7 +880,7 @@ mod tests {
         fn ten_draws_replay() -> Replay {
             Replay::new(
                 7,
-                DrawMode::DrawOne,
+                DrawStockConfig::DrawOne,
                 GameMode::Classic,
                 10,
                 100,

solitaire_engine/src/resources.rs

@@ -7,7 +7,7 @@ use bevy::math::Vec2;
 use bevy::prelude::Resource;
 use chrono::{DateTime, Utc};
 use solitaire_core::KlondikePile;
-use solitaire_core::card::Card;
+use solitaire_core::Card;
 use solitaire_core::game_state::GameState;
 
 /// Wraps the currently active `GameState`. Single source of truth for the in-progress game.

solitaire_engine/src/selection_plugin.rs

@@ -38,7 +38,7 @@
 use bevy::input::ButtonInput;
 use bevy::prelude::*;
 use solitaire_core::{Foundation, KlondikePile, Tableau};
-use solitaire_core::card::Card;
+use solitaire_core::Card;
 use solitaire_core::game_state::GameState;
 
 use crate::card_plugin::CardEntityIndex;
@@ -534,7 +534,7 @@ fn handle_selection_keys(
 /// destination after a lift. Players who want a different column simply
 /// press the right-arrow key once or twice.
 pub(crate) fn legal_destinations_for(
-    _bottom: &solitaire_core::card::Card,
+    _bottom: &solitaire_core::Card,
     source: &KlondikePile,
     game: &GameState,
     stack_count: usize,
@@ -579,7 +579,7 @@ pub(crate) fn legal_destinations_for(
 /// Walks backwards from the last element and stops at the first face-down card
 /// (or when the slice is exhausted). Returns at least `1` when the top card is
 /// face-up; returns `0` for an empty slice or when the top card is face-down.
-fn face_up_run_len(cards: &[(solitaire_core::card::Card, bool)]) -> usize {
+fn face_up_run_len(cards: &[(solitaire_core::Card, bool)]) -> usize {
     let mut count = 0;
     for (_, face_up) in cards.iter().rev() {
         if *face_up {
@@ -598,7 +598,7 @@ fn face_up_run_len(cards: &[(solitaire_core::card::Card, bool)]) -> usize {
 /// handler can attempt a foundation move first and fall through to a
 /// multi-card stack move rather than accepting a single-card tableau move.
 fn try_foundation_dest(
-    card: &solitaire_core::card::Card,
+    card: &solitaire_core::Card,
     game: &solitaire_core::game_state::GameState,
 ) -> Option<KlondikePile> {
     let source = game.pile_containing_card(card.clone())?;
@@ -886,7 +886,7 @@ mod tests {
 
     #[test]
     fn face_up_run_len_all_face_up() {
-        use solitaire_core::card::{Card, Deck, Rank, Suit};
+        use solitaire_core::{Card, Deck, Rank, Suit};
         let cards = vec![
             (Card::new(Deck::Deck1, Suit::Clubs, Rank::King), true),
             (Card::new(Deck::Deck1, Suit::Hearts, Rank::Queen), true),
@@ -897,7 +897,7 @@ mod tests {
 
     #[test]
     fn face_up_run_len_mixed_stops_at_face_down() {
-        use solitaire_core::card::{Card, Deck, Rank, Suit};
+        use solitaire_core::{Card, Deck, Rank, Suit};
         let cards = vec![
             (Card::new(Deck::Deck1, Suit::Clubs, Rank::King), false),
             (Card::new(Deck::Deck1, Suit::Hearts, Rank::Queen), false),
@@ -910,7 +910,7 @@ mod tests {
 
     #[test]
     fn face_up_run_len_top_card_face_down_is_zero() {
-        use solitaire_core::card::{Card, Deck, Rank, Suit};
+        use solitaire_core::{Card, Deck, Rank, Suit};
         let cards = vec![
             (Card::new(Deck::Deck1, Suit::Clubs, Rank::King), true),
             (Card::new(Deck::Deck1, Suit::Hearts, Rank::Queen), false),
@@ -920,7 +920,7 @@ mod tests {
 
     #[test]
     fn face_up_run_len_single_face_up_card() {
-        use solitaire_core::card::{Card, Deck, Rank, Suit};
+        use solitaire_core::{Card, Deck, Rank, Suit};
         let cards = vec![(Card::new(Deck::Deck1, Suit::Hearts, Rank::Ace), true)];
         assert_eq!(face_up_run_len(&cards), 1);
     }
@@ -934,8 +934,8 @@ mod tests {
     // -----------------------------------------------------------------------
 
     use bevy::ecs::message::Messages;
-    use solitaire_core::card::{Card, Deck, Rank, Suit};
+    use solitaire_core::{Card, Deck, Rank, Suit};
-    use solitaire_core::{DrawMode, game_state::GameState};
+    use solitaire_core::{DrawStockConfig, game_state::GameState};
 
     /// Build a minimal app with `SelectionPlugin` only — no GamePlugin, no
     /// AssetServer. The `MoveRequestEvent` / `StateChangedEvent` /
@@ -968,7 +968,7 @@ mod tests {
     /// Ace first). It cannot go to an empty tableau (only Kings).
     /// Empty tableaus T3..T6 only accept Kings, so they are filtered out.
     fn deterministic_state() -> GameState {
-        let mut g = GameState::new(0, DrawMode::DrawOne);
+        let mut g = GameState::new(0, DrawStockConfig::DrawOne);
         // Clear stock, waste, all tableaus.
         g.set_test_stock_cards(Vec::new());
         g.set_test_waste_cards(Vec::new());

solitaire_engine/src/settings_plugin.rs

@@ -15,7 +15,7 @@ use bevy::input::mouse::{MouseScrollUnit, MouseWheel};
 use bevy::prelude::*;
 use bevy::ui::{ComputedNode, UiGlobalTransform};
 use bevy::window::{WindowMoved, WindowResized};
-use solitaire_core::DrawMode;
+use solitaire_core::DrawStockConfig;
 use solitaire_data::{
     AnimSpeed, REPLAY_MOVE_INTERVAL_STEP_SECS, Settings, TIME_BONUS_MULTIPLIER_STEP,
     TOOLTIP_DELAY_STEP_SECS, WindowGeometry, load_settings_from, save_settings_to, settings::Theme,
@@ -241,7 +241,7 @@ enum SettingsButton {
     ToggleTouchInputMode,
     /// Toggle the [`Settings::winnable_deals_only`] flag. When on, new
     /// random Classic-mode deals are filtered through
-    /// [`solitaire_data::solver::try_solve`] until one is provably
+    /// [`solitaire_core::game_state::GameState::solve_fresh_deal`] until one is provably
     /// winnable (or the retry cap is hit). Off by default.
     ToggleWinnableDealsOnly,
     /// Toggle the inverse of [`Settings::disable_smart_default_size`].
@@ -1086,8 +1086,8 @@ fn handle_settings_buttons(
             }
             SettingsButton::ToggleDrawMode => {
                 settings.0.draw_mode = match settings.0.draw_mode {
-                    DrawMode::DrawOne => DrawMode::DrawThree,
+                    DrawStockConfig::DrawOne => DrawStockConfig::DrawThree,
-                    DrawMode::DrawThree => DrawMode::DrawOne,
+                    DrawStockConfig::DrawThree => DrawStockConfig::DrawOne,
                 };
                 persist(&path, &settings.0);
                 changed.write(SettingsChangedEvent(settings.0.clone()));
@@ -1310,10 +1310,10 @@ fn handle_sync_buttons(
     }
 }
 
-fn draw_mode_label(mode: &DrawMode) -> String {
+fn draw_mode_label(mode: &DrawStockConfig) -> String {
     match mode {
-        DrawMode::DrawOne => "Draw 1".into(),
+        DrawStockConfig::DrawOne => "Draw 1".into(),
-        DrawMode::DrawThree => "Draw 3".into(),
+        DrawStockConfig::DrawThree => "Draw 3".into(),
     }
 }
 

solitaire_engine/src/stats_plugin.rs

@@ -1327,7 +1327,7 @@ mod tests {
         app.world_mut()
             .resource_mut::<crate::resources::GameStateResource>()
             .0
-            .set_test_draw_mode(solitaire_core::DrawMode::DrawThree);
+            .set_test_draw_mode(solitaire_core::DrawStockConfig::DrawThree);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,
@@ -1952,7 +1952,7 @@ mod tests {
         let date = chrono::NaiveDate::from_ymd_opt(2026, 5, 8).expect("valid date");
         let mut r = solitaire_data::Replay::new(
             1,
-            solitaire_core::DrawMode::DrawOne,
+            solitaire_core::DrawStockConfig::DrawOne,
             solitaire_core::game_state::GameMode::Classic,
             time_seconds,
             0,

solitaire_engine/src/sync_plugin.rs

@@ -604,7 +604,7 @@ mod tests {
     /// would silently drop the link.
     #[test]
     fn upload_result_writes_share_url_into_replay_and_persists() {
-        use solitaire_core::{DrawMode, game_state::GameMode};
+        use solitaire_core::{DrawStockConfig, game_state::GameMode};
         use solitaire_data::{
             Replay, ReplayHistory, load_replay_history_from, save_replay_history_to,
         };
@@ -617,7 +617,7 @@ mod tests {
         // share_url — the upload-poll path must populate it.
         let initial = Replay::new(
             42,
-            DrawMode::DrawOne,
+            DrawStockConfig::DrawOne,
             GameMode::Classic,
             60,
             500,

solitaire_engine/src/table_plugin.rs

@@ -7,7 +7,7 @@
 use bevy::prelude::*;
 use bevy::window::WindowResized;
 use solitaire_core::{Foundation, KlondikePile, Tableau};
-use solitaire_core::card::Suit;
+use solitaire_core::Suit;
 
 use crate::events::{HintVisualEvent, StateChangedEvent};
 use crate::hud_plugin::HudVisibility;
@@ -520,7 +520,7 @@ fn sync_pile_marker_visibility(
 fn pile_cards(
     game: &solitaire_core::game_state::GameState,
     pile: &KlondikePile,
-) -> Vec<(solitaire_core::card::Card, bool)> {
+) -> Vec<(solitaire_core::Card, bool)> {
     match pile {
         KlondikePile::Stock => {
             let stock = game.stock_cards();

solitaire_engine/src/theme/mod.rs

@@ -27,7 +27,7 @@ use bevy::reflect::TypePath;
 use serde::{Deserialize, Serialize};
 use thiserror::Error;
 
-use solitaire_core::card::{Rank, Suit};
+use solitaire_core::{Rank, Suit};
 
 #[cfg(not(target_arch = "wasm32"))]
 pub use importer::{ImportError, ThemeId, import_theme, import_theme_into};

solitaire_engine/src/theme/plugin.rs

@@ -12,7 +12,7 @@ use bevy::asset::AssetEvent;
 use bevy::ecs::message::MessageReader;
 use bevy::math::UVec2;
 use bevy::prelude::*;
-use solitaire_core::card::{Rank, Suit};
+use solitaire_core::{Rank, Suit};
 
 use crate::assets::{
     bundled_theme_url, classic_theme_svg_bytes, dark_theme_svg_bytes, rasterize_svg, user_theme_dir,

solitaire_engine/src/time_attack_plugin.rs

@@ -299,7 +299,7 @@ mod tests {
     use crate::game_plugin::GamePlugin;
     use crate::progress_plugin::ProgressPlugin;
     use crate::table_plugin::TablePlugin;
-    use solitaire_core::{DrawMode, game_state::GameState};
+    use solitaire_core::{DrawStockConfig, game_state::GameState};
 
     fn headless_app() -> App {
         let mut app = App::new();
@@ -430,7 +430,7 @@ mod tests {
         };
         // The current game must be in TimeAttack mode for auto-deal to fire.
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new_with_mode(7, DrawMode::DrawOne, GameMode::TimeAttack);
+            GameState::new_with_mode(7, DrawStockConfig::DrawOne, GameMode::TimeAttack);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,
@@ -454,7 +454,7 @@ mod tests {
         let mut app = headless_app();
         // Default session is inactive. Game is TimeAttack mode — still no count.
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new_with_mode(7, DrawMode::DrawOne, GameMode::TimeAttack);
+            GameState::new_with_mode(7, DrawStockConfig::DrawOne, GameMode::TimeAttack);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,

solitaire_engine/src/touch_selection_plugin.rs

@@ -29,7 +29,7 @@
 use bevy::ecs::message::MessageReader;
 use bevy::prelude::*;
 use solitaire_core::KlondikePile;
-use solitaire_core::card::Card;
+use solitaire_core::Card;
 
 use crate::card_plugin::CardEntity;
 use crate::events::StateChangedEvent;
@@ -194,7 +194,7 @@ fn spawn_touch_highlight(
 mod tests {
     use super::*;
     use solitaire_core::Tableau;
-    use solitaire_core::card::{Card, Deck, Rank, Suit};
+    use solitaire_core::{Card, Deck, Rank, Suit};
 
     /// Three distinct test cards, used in place of the old `vec![1, 2, 3]`
     /// numeric ids. Identity is now the `Card` value.

solitaire_engine/src/weekly_goals_plugin.rs

@@ -82,7 +82,7 @@ fn evaluate_weekly_goals(
     for ev in events.drain(..) {
         let ctx = WeeklyGoalContext {
             time_seconds: ev.time_seconds,
-            used_undo: game.0.undo_count > 0,
+            used_undo: game.0.undo_count() > 0,
             draw_mode: game.0.draw_mode(),
         };
         for def in WEEKLY_GOALS {
@@ -177,7 +177,7 @@ mod tests {
         app.world_mut()
             .resource_mut::<GameStateResource>()
             .0
-            .undo_count = 1;
+            .force_test_undos(1);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,

solitaire_engine/src/win_summary_plugin.rs

@@ -90,28 +90,23 @@ pub struct WinSummaryPending {
 
 /// Builds a human-readable XP breakdown string for the win modal.
 ///
-/// Mirrors the logic in `solitaire_data::xp_for_win` so the breakdown always
+/// Reads the components from `solitaire_data::xp_breakdown` — the single source
-/// matches the total shown on the `XpAwardedEvent`.
+/// of truth shared with `xp_for_win` — so the breakdown can never drift from
+/// the total shown on the `XpAwardedEvent`.
 ///
 /// Examples:
 /// - slow win, no undo  → `"+50 base  +25 no-undo"`
 /// - fast win, undo     → `"+50 base  +30 speed"`
 /// - fast win, no undo  → `"+50 base  +25 no-undo  +30 speed"`
 fn build_xp_detail(time_seconds: u64, used_undo: bool) -> String {
-    let speed_bonus: u64 = if time_seconds >= 120 {
+    let xp = solitaire_data::xp_breakdown(time_seconds, used_undo);
-        0
-    } else {
-        let scaled = 50_u64.saturating_sub(time_seconds.saturating_mul(40) / 120);
-        scaled.max(10)
-    };
-    let no_undo_bonus: u64 = if used_undo { 0 } else { 25 };
 
-    let mut parts = vec!["+50 base".to_string()];
+    let mut parts = vec![format!("+{} base", xp.base)];
-    if no_undo_bonus > 0 {
+    if xp.no_undo_bonus > 0 {
-        parts.push("+25 no-undo".to_string());
+        parts.push(format!("+{} no-undo", xp.no_undo_bonus));
     }
-    if speed_bonus > 0 {
+    if xp.speed_bonus > 0 {
-        parts.push(format!("+{speed_bonus} speed"));
+        parts.push(format!("+{} speed", xp.speed_bonus));
     }
     parts.join("  ")
 }
@@ -477,14 +472,14 @@ fn cache_win_data(
             None
         };
 
-        let used_undo = game.0.undo_count > 0;
+        let used_undo = game.0.undo_count() > 0;
         pending.score = ev.score;
         pending.time_seconds = ev.time_seconds;
         pending.xp = 0; // reset; XP event follows
         pending.xp_detail = build_xp_detail(ev.time_seconds, used_undo);
         pending.new_record = is_new_record;
         pending.challenge_level = challenge_level;
-        pending.undo_count = game.0.undo_count;
+        pending.undo_count = game.0.undo_count();
         pending.mode = game.0.mode;
 
         if is_new_record {
@@ -1210,7 +1205,7 @@ mod tests {
             .insert_resource(StatsResource(StatsSnapshot::default()))
             .insert_resource(GameStateResource(GameState::new(
                 0,
-                solitaire_core::DrawMode::DrawOne,
+                solitaire_core::DrawStockConfig::DrawOne,
             )))
             .insert_resource(ProgressResource(PlayerProgress::default()));
         app.update();
@@ -1539,9 +1534,9 @@ mod tests {
             .challenge_index = 4;
         // Switch game mode to Challenge.
         {
-            use solitaire_core::DrawMode;
+            use solitaire_core::DrawStockConfig;
             app.world_mut().resource_mut::<GameStateResource>().0 =
-                GameState::new_with_mode(1, DrawMode::DrawOne, GameMode::Challenge);
+                GameState::new_with_mode(1, DrawStockConfig::DrawOne, GameMode::Challenge);
         }
 
         app.world_mut().write_message(GameWonEvent {
@@ -1585,14 +1580,14 @@ mod tests {
     /// mode-multiplier rows.
     #[test]
     fn cache_win_data_captures_undo_count_and_mode() {
-        use solitaire_core::DrawMode;
+        use solitaire_core::DrawStockConfig;
 
         let mut app = make_app();
         // Set up a Zen-mode game with 2 undos used.
         {
             let mut game = app.world_mut().resource_mut::<GameStateResource>();
-            game.0 = GameState::new_with_mode(7, DrawMode::DrawOne, GameMode::Zen);
+            game.0 = GameState::new_with_mode(7, DrawStockConfig::DrawOne, GameMode::Zen);
-            game.0.undo_count = 2;
+            game.0.force_test_undos(2);
         }
 
         app.world_mut().write_message(GameWonEvent {

solitaire_wasm/src/lib.rs

@@ -21,9 +21,9 @@
 use chrono::NaiveDate;
 use solitaire_core::{Foundation, KlondikePile, Tableau};
 use serde::{Deserialize, Serialize};
-use solitaire_core::card::Suit;
+use solitaire_core::{Card, Deck, Rank, Suit};
 use solitaire_core::error::MoveError;
-use solitaire_core::{DrawMode, game_state::{GameMode, GameState}};
+use solitaire_core::{DrawStockConfig, game_state::{GameMode, GameState}};
 use solitaire_core::klondike_adapter::{
     SavedInstruction, SavedKlondikePile, SavedKlondikePileStack, tableau_from_index,
 };
@@ -48,7 +48,7 @@ pub struct Replay {
     #[serde(default)]
     pub schema_version: u32,
     pub seed: u64,
-    pub draw_mode: DrawMode,
+    pub draw_mode: DrawStockConfig,
     pub mode: GameMode,
     pub time_seconds: u64,
     pub final_score: i32,
@@ -77,9 +77,11 @@ pub struct StateSnapshot {
 /// means the card back is drawn; in that case `suit` and `rank` are
 /// still set (so the renderer doesn't need separate "unknown" data),
 /// just hidden visually.
-#[derive(Debug, Clone, Copy, Serialize, PartialEq, Eq)]
+#[derive(Debug, Clone, Serialize, PartialEq, Eq)]
 pub struct CardSnapshot {
-    pub id: u32,
+    /// Stable per-card identity for the JS renderer (an opaque key). Serialises
+    /// as the upstream `Card`'s transparent integer value.
+    pub id: Card,
     /// `"clubs" | "diamonds" | "hearts" | "spades"`.
     pub suit: &'static str,
     /// 1-13, where 1 is Ace and 13 is King.
@@ -87,14 +89,10 @@ pub struct CardSnapshot {
     pub face_up: bool,
 }
 
-// Stable 0..=51 card identity, shared with the desktop engine via
+impl From<&(Card, bool)> for CardSnapshot {
-// solitaire_core so replay snapshots are identical across platforms.
+    fn from((card, face_up): &(Card, bool)) -> Self {
-use solitaire_core::card::card_to_id;
-
-impl From<&(solitaire_core::card::Card, bool)> for CardSnapshot {
-    fn from((card, face_up): &(solitaire_core::card::Card, bool)) -> Self {
         Self {
-            id: card_to_id(card),
+            id: card.clone(),
             suit: match card.suit() {
                 Suit::Clubs => "clubs",
                 Suit::Diamonds => "diamonds",
@@ -184,7 +182,7 @@ impl ReplayPlayer {
         StateSnapshot {
             step_idx: self.step_idx,
             total_steps: self.moves.len(),
-            score: self.game.score,
+            score: self.game.score(),
             move_count: self.game.move_count(),
             is_won: self.game.is_won(),
             stock: self
@@ -318,9 +316,10 @@ pub enum DebugMove {
 pub struct DebugInvariantReport {
     pub state_ok: bool,
     pub total_cards_seen: usize,
-    pub duplicate_card_ids: Vec<u32>,
+    /// Cards that appeared more than once across all piles.
-    pub missing_card_ids: Vec<u32>,
+    pub duplicate_cards: Vec<Card>,
-    pub out_of_range_card_ids: Vec<u32>,
+    /// Cards from the full single-deck set that are absent from the board.
+    pub missing_cards: Vec<Card>,
     pub stock_has_face_up_cards: bool,
     pub waste_has_face_down_cards: bool,
     pub foundation_has_face_down_cards: bool,
@@ -332,7 +331,7 @@ pub struct DebugInvariantReport {
 #[derive(Debug, Clone, Serialize, PartialEq, Eq)]
 pub struct DebugSnapshot {
     pub seed: u64,
-    pub draw_mode: DrawMode,
+    pub draw_mode: DrawStockConfig,
     pub mode: GameMode,
     pub state: GameSnapshot,
     pub legal_moves: Vec<DebugMove>,
@@ -389,24 +388,15 @@ fn invariant_report_for_game(game: &GameState, legal_moves: &[DebugMove]) -> Deb
         game.pile(KlondikePile::Tableau(Tableau::Tableau7)),
     ];
 
-    let mut seen = [false; 52];
+    let mut seen: std::collections::HashSet<Card> = std::collections::HashSet::new();
-    let mut duplicate_card_ids = Vec::new();
+    let mut duplicate_cards = Vec::new();
-    let mut out_of_range_card_ids = Vec::new();
     let mut total_cards_seen = 0_usize;
 
-    let mut feed = |cards: &[(solitaire_core::card::Card, bool)]| {
+    let mut feed = |cards: &[(Card, bool)]| {
         for (card, _) in cards {
             total_cards_seen += 1;
-            let id = card_to_id(card);
+            if !seen.insert(card.clone()) {
-            if id >= 52 {
+                duplicate_cards.push(card.clone());
-                out_of_range_card_ids.push(id);
-                continue;
-            }
-            let idx = id as usize;
-            if seen[idx] {
-                duplicate_card_ids.push(id);
-            } else {
-                seen[idx] = true;
             }
         }
     };
@@ -420,9 +410,22 @@ fn invariant_report_for_game(game: &GameState, legal_moves: &[DebugMove]) -> Deb
         feed(pile);
     }
 
-    let missing_card_ids = (0_u32..52_u32)
+    // Reference set: the full 52-card single deck, using whichever deck id the
-        .filter(|id| !seen[*id as usize])
+    // dealt cards carry. Any of those 52 not on the board is missing.
-        .collect::<Vec<_>>();
+    let deck = seen
+        .iter()
+        .next()
+        .map(|c| c.deck())
+        .unwrap_or_else(|| Deck::new(0).expect("deck id 0 is valid"));
+    let mut missing_cards = Vec::new();
+    for suit in Suit::SUITS {
+        for rank in Rank::RANKS {
+            let card = Card::new(deck, suit, rank);
+            if !seen.contains(&card) {
+                missing_cards.push(card);
+            }
+        }
+    }
 
     let stock_has_face_up_cards = stock.iter().any(|(_, face_up)| *face_up);
     let waste_has_face_down_cards = waste.iter().any(|(_, face_up)| !*face_up);
@@ -444,9 +447,8 @@ fn invariant_report_for_game(game: &GameState, legal_moves: &[DebugMove]) -> Deb
 
     let soft_lock = !game.is_won() && stock.is_empty() && waste.is_empty() && legal_moves.is_empty();
 
-    let state_ok = duplicate_card_ids.is_empty()
+    let state_ok = duplicate_cards.is_empty()
-        && missing_card_ids.is_empty()
+        && missing_cards.is_empty()
-        && out_of_range_card_ids.is_empty()
         && !stock_has_face_up_cards
         && !waste_has_face_down_cards
         && !foundation_has_face_down_cards
@@ -455,9 +457,8 @@ fn invariant_report_for_game(game: &GameState, legal_moves: &[DebugMove]) -> Deb
     DebugInvariantReport {
         state_ok,
         total_cards_seen,
-        duplicate_card_ids,
+        duplicate_cards,
-        missing_card_ids,
+        missing_cards,
-        out_of_range_card_ids,
         stock_has_face_up_cards,
         waste_has_face_down_cards,
         foundation_has_face_down_cards,
@@ -487,12 +488,12 @@ impl SolitaireGame {
             !stock_empty || !waste_empty || !self.game.possible_instructions().is_empty()
         };
         GameSnapshot {
-            score: self.game.score,
+            score: self.game.score(),
             move_count: self.game.move_count(),
             is_won: self.game.is_won(),
             is_auto_completable: self.game.is_auto_completable(),
             has_moves,
-            undo_count: self.game.undo_count,
+            undo_count: self.game.undo_count(),
             undo_stack_len: self.game.undo_stack_len(),
             stock: self
                 .game
@@ -726,9 +727,9 @@ impl SolitaireGame {
         #[cfg(feature = "console_error_panic_hook")]
         console_error_panic_hook::set_once();
         let dm = if draw_three {
-            DrawMode::DrawThree
+            DrawStockConfig::DrawThree
         } else {
-            DrawMode::DrawOne
+            DrawStockConfig::DrawOne
         };
         SolitaireGame {
             game: GameState::new_with_mode(seed as u64, dm, GameMode::Classic),
@@ -893,6 +894,25 @@ mod tests {
     use std::collections::HashSet;
     use std::fmt::Write;
 
+    /// The JS card renderer reads `card.id` as an opaque identity key. After the
+    /// `card_to_id` removal, `CardSnapshot.id` is a `card_game::Card`, which is
+    /// `#[serde(transparent)]` over `NonZeroU8` — so it must still serialise as a
+    /// plain JSON number (the same `Serialize` impl `serde_wasm_bindgen` uses).
+    #[test]
+    fn card_snapshot_id_serialises_as_a_plain_number() {
+        let card = Card::new(Deck::new(0).unwrap(), Suit::Hearts, Rank::RANKS[0]);
+        let snap = CardSnapshot::from(&(card, true));
+        let json = serde_json::to_value(&snap).expect("serialise CardSnapshot");
+        assert!(
+            json["id"].is_number(),
+            "card.id must serialise as a JSON number for the JS opaque key, got {:?}",
+            json["id"]
+        );
+        assert_eq!(json["suit"], "hearts");
+        assert_eq!(json["rank"], 1);
+        assert_eq!(json["face_up"], true);
+    }
+
     fn pick_move_index(moves: &[DebugMove]) -> Option<usize> {
         if moves.is_empty() {
             return None;
@@ -933,7 +953,7 @@ mod tests {
             for card in cards {
                 let _ = write!(
                     key,
-                    "{}:{}:{},",
+                    "{:?}:{}:{},",
                     card.id,
                     card.rank,
                     if card.face_up { 1 } else { 0 }
@@ -952,7 +972,7 @@ mod tests {
         key
     }
 
-    fn run_autonomous(seed: u64, draw_mode: DrawMode, max_steps: usize) -> DebugSnapshot {
+    fn run_autonomous(seed: u64, draw_mode: DrawStockConfig, max_steps: usize) -> DebugSnapshot {
         let mut game = SolitaireGame {
             game: GameState::new_with_mode(seed, draw_mode, GameMode::Classic),
         };
@@ -983,7 +1003,7 @@ mod tests {
     #[test]
     fn debug_snapshot_exposes_replayable_seed_and_history() {
         let seed = 42_u64;
-        let final_snapshot = run_autonomous(seed, DrawMode::DrawOne, 1500);
+        let final_snapshot = run_autonomous(seed, DrawStockConfig::DrawOne, 1500);
         assert_eq!(final_snapshot.seed, seed);
         assert!(
             !final_snapshot.state_json.is_empty(),
@@ -1000,7 +1020,7 @@ mod tests {
     #[test]
     fn replay_moves_export_is_json_compatible_and_replayable() {
         let seed = 7_u64;
-        let draw_mode = DrawMode::DrawThree;
+        let draw_mode = DrawStockConfig::DrawThree;
         let mut game = SolitaireGame {
             game: GameState::new_with_mode(seed, draw_mode, GameMode::Classic),
         };
@@ -1059,7 +1079,7 @@ mod tests {
             draw_mode,
             mode: GameMode::Classic,
             time_seconds: 120,
-            final_score: game.game.score,
+            final_score: game.game.score(),
             recorded_at,
             moves: exported_moves,
         };
@@ -1098,9 +1118,9 @@ mod tests {
     fn debug_api_autonomous_seed_batch_smoke() {
         for seed in 0_u64..128_u64 {
             let draw_mode = if seed % 2 == 0 {
-                DrawMode::DrawOne
+                DrawStockConfig::DrawOne
             } else {
-                DrawMode::DrawThree
+                DrawStockConfig::DrawThree
             };
             let snapshot = run_autonomous(seed, draw_mode, 2000);
             assert_invariants(&snapshot, seed);
@@ -1112,9 +1132,9 @@ mod tests {
     fn debug_api_autonomous_thousands_seed_soak() {
         for seed in 10_000_u64..12_000_u64 {
             let draw_mode = if seed % 2 == 0 {
-                DrawMode::DrawOne
+                DrawStockConfig::DrawOne
             } else {
-                DrawMode::DrawThree
+                DrawStockConfig::DrawThree
             };
             let snapshot = run_autonomous(seed, draw_mode, 3000);
             assert_invariants(&snapshot, seed);
@@ -1125,7 +1145,7 @@ mod tests {
     fn serialize_from_saved_round_trip() {
         let seed = 55_u64;
         let mut game = SolitaireGame {
-            game: GameState::new_with_mode(seed, DrawMode::DrawOne, GameMode::Classic),
+            game: GameState::new_with_mode(seed, DrawStockConfig::DrawOne, GameMode::Classic),
         };
         // Advance a few moves so there is non-trivial state to round-trip.
         for _ in 0..20 {
@@ -1160,7 +1180,7 @@ mod tests {
     fn undo_reverts_to_prior_state() {
         let seed = 99_u64;
         let mut game = SolitaireGame {
-            game: GameState::new_with_mode(seed, DrawMode::DrawOne, GameMode::Classic),
+            game: GameState::new_with_mode(seed, DrawStockConfig::DrawOne, GameMode::Classic),
         };
 
         let before_key = board_key(&game.debug_snapshot_native().state);
@@ -1198,7 +1218,7 @@ mod tests {
     fn draw_one_advances_waste_by_one() {
         let seed = 1_u64;
         let mut game = SolitaireGame {
-            game: GameState::new_with_mode(seed, DrawMode::DrawOne, GameMode::Classic),
+            game: GameState::new_with_mode(seed, DrawStockConfig::DrawOne, GameMode::Classic),
         };
 
         let stock_before = game.game.stock_cards().len();
@@ -1224,7 +1244,7 @@ mod tests {
     fn draw_three_advances_waste_by_three() {
         let seed = 1_u64;
         let mut game = SolitaireGame {
-            game: GameState::new_with_mode(seed, DrawMode::DrawThree, GameMode::Classic),
+            game: GameState::new_with_mode(seed, DrawStockConfig::DrawThree, GameMode::Classic),
         };
 
         let stock_before = game.game.stock_cards().len();
@@ -1254,7 +1274,7 @@ mod tests {
     fn debug_apply_move_json_stock_click_advances_waste() {
         let seed = 3_u64;
         let mut game = SolitaireGame {
-            game: GameState::new_with_mode(seed, DrawMode::DrawOne, GameMode::Classic),
+            game: GameState::new_with_mode(seed, DrawStockConfig::DrawOne, GameMode::Classic),
         };
 
         let waste_before = game.game.waste_cards().len();