refactor(engine,wasm,data): route all klondike/card_game imports through solitaire_core

All downstream crates now import Foundation, KlondikePile, Tableau,
Klondike, Session, Suit, Rank exclusively from solitaire_core.
solitaire_core is the single version-pin point for the upstream crates.

- solitaire_engine: 19 files updated, klondike direct dep removed
- solitaire_wasm: use statement updated, klondike direct dep removed
- solitaire_data: unused klondike dep removed
- Cargo.lock: klondike no longer a direct dep of engine/wasm/data
- Full workspace clippy clean, all tests pass

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

solitaire_engine/src/animation_plugin.rs

@@ -1078,7 +1078,7 @@ mod tests {
         // Pairs the existing audio (`card_invalid.wav`) and visual
         // (`feedback_anim_plugin::queue_shake_for_rejected_move`) feedback
         // with an accessibility-focused readable text cue.
-        use klondike::{KlondikePile, Tableau};
+        use solitaire_core::{KlondikePile, Tableau};
         let mut app = App::new();
         app.add_plugins(MinimalPlugins).add_plugins(AnimationPlugin);
 

solitaire_engine/src/auto_complete_plugin.rs

@@ -167,7 +167,7 @@ mod tests {
     use super::*;
     use crate::game_plugin::GamePlugin;
     use crate::table_plugin::TablePlugin;
-    use klondike::{Foundation, KlondikePile, Tableau};
+    use solitaire_core::{Foundation, KlondikePile, Tableau};
     use solitaire_core::card::{Rank, Suit};
     use solitaire_core::game_state::{DrawMode, GameState};
 

solitaire_engine/src/card_plugin.rs

@@ -16,7 +16,7 @@ use bevy::color::Color;
 use bevy::prelude::*;
 use bevy::sprite::Anchor;
 use bevy::window::WindowResized;
-use klondike::{Foundation, KlondikePile, Tableau};
+use solitaire_core::{Foundation, KlondikePile, Tableau};
 use solitaire_core::card::{Card, Rank, Suit};
 use solitaire_core::game_state::{DrawMode, GameState};
 
@@ -230,7 +230,7 @@ pub struct StockEmptyLabel;
 /// The badge is spawned as a *top-level* world entity (not parented to the
 /// stock [`PileMarker`]) and its `Transform` is recomputed each frame from
 /// `LayoutResource` so it tracks the stock pile through window resizes.
-/// The chip sits in the top-right corner of the stock pile and is hidden
+/// The chip sits in the bottom-right corner of the stock pile and is hidden
 /// while the stock is empty — the existing `↺` overlay
 /// ([`StockEmptyLabel`]) covers the recycle hint instead, so the two
 /// indicators never render simultaneously.
@@ -301,13 +301,18 @@ pub struct CardShadow;
 #[derive(Component, Debug)]
 pub struct CardBackFrame;
 
-/// Fill colour for the face-down card border frame. Medium gray so it reads as
-/// a neutral "edge" without competing with the suit colours on face-up cards.
-const CARD_BACK_FRAME_COLOR: Color = Color::srgb(0.38, 0.38, 0.38);
+/// Fill colour for the face-down card border frame. Light-medium gray so it
+/// reads as a clear "edge" without competing with the suit colours on face-up
+/// cards. Brightened from `0.38` to `0.48` (≈ #7a7a7a) after a Pixel_7 smoke
+/// test showed face-down `back_0.png` (≈ #1a1a1a) was nearly invisible against
+/// the very dark `#151515` felt — the old gray was too close to the back fill
+/// to define a crisp perimeter.
+const CARD_BACK_FRAME_COLOR: Color = Color::srgb(0.48, 0.48, 0.48);
 
 /// Extra width/height (in world units) added to each side of the card to form
-/// the visible border. 3 world units ≈ 3 dp on a 1× screen.
-const CARD_BACK_FRAME_PADDING: f32 = 3.0;
+/// the visible border. Widened from `3.0` to `6.0` so the frame peeks out as a
+/// clearly readable perimeter at phone density (420 dpi) rather than a hairline.
+const CARD_BACK_FRAME_PADDING: f32 = 6.0;
 
 /// Returns the `(offset, padding, alpha)` triple used to paint a per-card
 /// shadow given whether its parent card is currently part of the dragged
@@ -1901,19 +1906,22 @@ fn update_stock_empty_indicator(
 // ---------------------------------------------------------------------------
 // Stock-pile remaining-count badge
 //
-// Shows a small "N" chip pinned to the top-right corner of the stock pile so
+// Shows a small "N" chip pinned to the bottom-right corner of the stock pile so
 // the player can see how many cards remain before the next recycle. The
 // existing `StockEmptyLabel` (`↺` overlay) covers the empty-stock case, so
 // the badge hides itself when the stock has zero cards — the two indicators
 // never render at the same time.
 // ---------------------------------------------------------------------------
 
-/// Inset (in pixels) from the top-right corner of the stock pile sprite to
-/// the centre of the count badge. Must satisfy `|x| >= STOCK_BADGE_SIZE.x / 2`
-/// so the badge right edge stays inside the stock pile and never overlaps the
-/// adjacent waste pile — critical on Android where `H_GAP_DIVISOR = 32` gives
-/// an inter-pile gap of only ~4 px.
-const STOCK_BADGE_INSET: Vec2 = Vec2::new(-20.0, -8.0);
+/// Inset (in pixels) from the bottom-right corner of the stock pile sprite to
+/// the centre of the count badge. Anchoring to the bottom-right keeps the chip
+/// clear of the rank/suit pip in the card's top-left corner. Both components
+/// move the centre *inward* from that corner: `x` is subtracted from the right
+/// edge, `y` is added to the bottom edge. The `x` magnitude must satisfy
+/// `x >= STOCK_BADGE_SIZE.x / 2` so the badge right edge stays inside the stock
+/// pile and never overlaps the adjacent waste pile — critical on Android where
+/// `H_GAP_DIVISOR = 32` gives an inter-pile gap of only ~4 px.
+const STOCK_BADGE_INSET: Vec2 = Vec2::new(20.0, 8.0);
 
 /// Width / height of the badge background sprite, in world pixels. Sized so
 /// a 2-digit count (max "24") fits comfortably with `TYPE_BODY` (14 pt) text.
@@ -1928,8 +1936,9 @@ fn stock_card_count(game: &GameState) -> usize {
 }
 
 /// Returns the world-space `Vec3` for the centre of the stock-count badge,
-/// given the current `Layout`. The badge sits at the top-right corner of
-/// the stock pile sprite, inset by [`STOCK_BADGE_INSET`].
+/// given the current `Layout`. The badge sits at the bottom-right corner of
+/// the stock pile sprite, inset by [`STOCK_BADGE_INSET`], so it stays clear of
+/// the rank/suit pip in the card's top-left corner.
 fn stock_badge_translation(layout: &Layout) -> Vec3 {
     // Empty layouts don't contain a Stock entry — fall back to origin so
     // the badge stays in a deterministic spot until the layout is filled.
@@ -1939,8 +1948,9 @@ fn stock_badge_translation(layout: &Layout) -> Vec3 {
         .copied()
         .unwrap_or(Vec2::ZERO);
     let half = layout.card_size * 0.5;
-    let x = pile_pos.x + half.x + STOCK_BADGE_INSET.x;
-    let y = pile_pos.y + half.y + STOCK_BADGE_INSET.y;
+    // Anchor to the bottom-right corner, then move the centre inward.
+    let x = pile_pos.x + half.x - STOCK_BADGE_INSET.x;
+    let y = pile_pos.y - half.y + STOCK_BADGE_INSET.y;
     Vec3::new(x, y, Z_STOCK_BADGE)
 }
 
@@ -2357,7 +2367,7 @@ fn update_tableau_fan_frac(
     .into_iter()
     .map(|tableau| {
         game.0
-            .pile(klondike::KlondikePile::Tableau(tableau))
+            .pile(solitaire_core::KlondikePile::Tableau(tableau))
             .into_iter()
             .filter(|c| c.face_up)
             .count()

solitaire_engine/src/cursor_plugin.rs

@@ -34,7 +34,7 @@
 
 use bevy::prelude::*;
 use bevy::window::{CursorIcon, PrimaryWindow, SystemCursorIcon};
-use klondike::{Foundation, KlondikePile, Tableau};
+use solitaire_core::{Foundation, KlondikePile, Tableau};
 use solitaire_core::game_state::{DrawMode, GameState};
 
 use crate::card_plugin::RightClickHighlight;
@@ -655,7 +655,7 @@ mod tests {
             .world_mut()
             .query::<&DropTargetOverlay>()
             .iter(app.world())
-            .map(|o| o.0.clone())
+            .map(|o| o.0)
             .collect();
         assert!(
             !overlays.contains(&KlondikePile::Tableau(Tableau::Tableau3)),

solitaire_engine/src/events.rs

@@ -1,7 +1,7 @@
 //! Cross-system events used by the engine's plugins.
 
 use bevy::prelude::Message;
-use klondike::KlondikePile;
+use solitaire_core::KlondikePile;
 use solitaire_core::card::Suit;
 use solitaire_core::game_state::GameMode;
 use solitaire_data::AchievementRecord;

solitaire_engine/src/feedback_anim_plugin.rs

@@ -43,7 +43,7 @@ use std::hash::{Hash, Hasher};
 
 use bevy::prelude::*;
 use bevy::window::RequestRedraw;
-use klondike::{Foundation, KlondikePile};
+use solitaire_core::{Foundation, KlondikePile};
 use solitaire_data::AnimSpeed;
 
 use crate::animation_plugin::CardAnim;
@@ -849,7 +849,7 @@ mod tests {
     #[test]
     fn shake_anim_skipped_under_reduce_motion() {
         use bevy::ecs::message::Messages;
-        use klondike::Tableau;
+        use solitaire_core::Tableau;
         use solitaire_core::game_state::{DrawMode, GameState};
         use solitaire_data::Settings;
 

solitaire_engine/src/game_plugin.rs

@@ -13,7 +13,7 @@ use chrono::Utc;
 use bevy::prelude::*;
 use bevy::tasks::{AsyncComputeTaskPool, Task, futures_lite::future};
 use bevy::window::AppLifecycle;
-use klondike::KlondikePile;
+use solitaire_core::KlondikePile;
 use solitaire_core::game_state::{DrawMode, GameMode, GameState};
 use solitaire_core::solver::{SolverConfig, SolverResult, try_solve};
 #[allow(deprecated)]
@@ -521,7 +521,7 @@ fn handle_new_game(
         // hides that information and reads naturally as "dealt from the
         // deck." Skipped when LayoutResource isn't present (headless tests).
         if let Some(layout) = layout.as_ref()
-            && let Some(stock) = layout.0.pile_positions.get(&klondike::KlondikePile::Stock)
+            && let Some(stock) = layout.0.pile_positions.get(&solitaire_core::KlondikePile::Stock)
         {
             for mut tx in &mut card_transforms {
                 tx.translation.x = stock.x;
@@ -1014,12 +1014,12 @@ fn pile_cards(game: &GameState, pile: &KlondikePile) -> Vec<solitaire_core::card
     }
 }
 
-fn foundation_slot(foundation: klondike::Foundation) -> Option<u8> {
+fn foundation_slot(foundation: solitaire_core::Foundation) -> Option<u8> {
     match foundation {
-        klondike::Foundation::Foundation1 => Some(0),
-        klondike::Foundation::Foundation2 => Some(1),
-        klondike::Foundation::Foundation3 => Some(2),
-        klondike::Foundation::Foundation4 => Some(3),
+        solitaire_core::Foundation::Foundation1 => Some(0),
+        solitaire_core::Foundation::Foundation2 => Some(1),
+        solitaire_core::Foundation::Foundation3 => Some(2),
+        solitaire_core::Foundation::Foundation4 => Some(3),
     }
 }
 
@@ -1294,7 +1294,7 @@ fn save_game_state_on_exit(
 #[cfg(test)]
 mod tests {
     use super::*;
-    use klondike::{Foundation, KlondikePile, Tableau};
+    use solitaire_core::{Foundation, KlondikePile, Tableau};
     use solitaire_core::klondike_adapter::{SavedKlondikePile, SavedTableau};
 
     /// Build a minimal headless `App` with just `GamePlugin` installed.
@@ -1423,8 +1423,10 @@ mod tests {
             "fresh game should inherit default take_from_foundation=true",
         );
 
-        let mut settings = solitaire_data::Settings::default();
-        settings.take_from_foundation = false;
+        let mut settings = solitaire_data::Settings {
+            take_from_foundation: false,
+            ..Default::default()
+        };
         app.world_mut()
             .write_message(crate::settings_plugin::SettingsChangedEvent(
                 settings.clone(),
@@ -1951,15 +1953,15 @@ mod tests {
         );
     }
 
-    /// Verify that the game-over overlay contains the expected header text and
-    /// action-hint strings so players understand why the overlay appeared and
-    /// what keys to press.
+    // Verify that the game-over overlay contains the expected header text and
+    // action-hint strings so players understand why the overlay appeared and
+    // what keys to press.
     // -----------------------------------------------------------------------
     // Task #56 — Escape dismisses GameOverScreen and starts new game
     // -----------------------------------------------------------------------
 
-    /// Pressing Escape while `GameOverScreen` is visible must fire
-    /// `NewGameRequestEvent` — identical behaviour to pressing N.
+    // Pressing Escape while `GameOverScreen` is visible must fire
+    // `NewGameRequestEvent` — identical behaviour to pressing N.
     // -----------------------------------------------------------------------
     // Task #48 — Undo with empty stack fires InfoToastEvent
     // -----------------------------------------------------------------------

solitaire_engine/src/hud_plugin.rs

@@ -8,7 +8,7 @@
 
 use bevy::prelude::*;
 use bevy::window::WindowResized;
-use klondike::{Foundation, KlondikePile, Tableau};
+use solitaire_core::{Foundation, KlondikePile, Tableau};
 use solitaire_core::card::Suit;
 use solitaire_core::game_state::{DrawMode, GameMode};
 
@@ -315,17 +315,17 @@ pub struct HintButton;
 /// Android HUD label for the Hint button — shared with the help screen's
 /// controls reference so both always agree.
 #[cfg(target_os = "android")]
-pub(crate) const ANDROID_HINT_LABEL: &str = "!";
+pub(crate) const ANDROID_HINT_LABEL: &str = "Hint";
 
 #[cfg(target_os = "android")]
 const ACTION_BAR_LABELS: [&str; 7] = [
-    "\u{2261}",
-    "\u{2190}",
-    "||",
-    "?",
+    "Menu",
+    "Undo",
+    "Pause",
+    "Help",
     ANDROID_HINT_LABEL,
-    "M",
-    "+",
+    "Mode",
+    "New",
 ];
 #[cfg(not(target_os = "android"))]
 const ACTION_BAR_LABELS: [&str; 7] = [
@@ -830,6 +830,8 @@ fn spawn_avatar_child(
 ) {
     const SIZE: f32 = 32.0;
     if let Some(handle) = avatar.and_then(|a| a.0.clone()) {
+        // Logged-in with a downloaded avatar: keep the accent disc behind it.
+        commands.entity(parent).insert(BackgroundColor(ACCENT_PRIMARY));
         // Image fills the circle container; border_radius clips it to a disc.
         commands.entity(parent).with_children(|b| {
             b.spawn((
@@ -850,6 +852,15 @@ fn spawn_avatar_child(
             })
             .and_then(|c| c.to_uppercase().next())
             .unwrap_or('?');
+        // Real initial (logged in) keeps the red accent disc; the '?'
+        // unauthenticated fallback uses a neutral grey so it reads as a
+        // "tap to log in" affordance rather than an error.
+        let disc_bg = if initial == '?' {
+            BG_ELEVATED_HI
+        } else {
+            ACCENT_PRIMARY
+        };
+        commands.entity(parent).insert(BackgroundColor(disc_bg));
         commands.entity(parent).with_children(|b| {
             b.spawn((
                 Text::new(initial.to_string()),
@@ -1651,11 +1662,13 @@ impl Default for HudActionFade {
 /// How many pixels from the bottom edge the cursor must be to reveal the bar.
 /// Set slightly taller than `HUD_BAND_HEIGHT` so the bar fades in as the
 /// cursor approaches, not only when it crosses into the band itself.
+#[cfg(not(target_os = "android"))]
 const ACTION_FADE_REVEAL_PX: f32 = HUD_BAND_HEIGHT + 32.0;
 
 /// Lerp rate for fading (per second). 6.0 ≈ 167 ms for a full
 /// transition — fast enough to feel responsive without flashing on
 /// brief cursor wanders into the reveal zone.
+#[cfg(not(target_os = "android"))]
 const ACTION_FADE_RATE_PER_SEC: f32 = 6.0;
 
 /// Updates the fade state from cursor position. Sets `target = 1.0` if
@@ -1663,6 +1676,7 @@ const ACTION_FADE_RATE_PER_SEC: f32 = 6.0;
 /// (player is using keyboard); `0.0` otherwise. Lerps `alpha` toward
 /// `target` at a fixed rate so the visual transition is smooth across
 /// variable framerates.
+#[cfg(not(target_os = "android"))]
 fn update_action_fade(windows: Query<&Window>, time: Res<Time>, mut fade: ResMut<HudActionFade>) {
     let Ok(window) = windows.single() else {
         return;
@@ -1687,6 +1701,7 @@ fn update_action_fade(windows: Query<&Window>, time: Res<Time>, mut fade: ResMut
 /// `Last` (after `paint_action_buttons`) so a hover-state change in the
 /// same frame doesn't override the fade with an opaque idle / hover
 /// colour.
+#[cfg(not(target_os = "android"))]
 #[allow(clippy::type_complexity)]
 fn apply_action_fade(
     fade: Res<HudActionFade>,
@@ -2567,10 +2582,18 @@ fn restore_hud_on_modal(
 /// Returns the action-bar label font size for a given logical window width.
 fn action_bar_font_size(window_width: f32) -> f32 {
     if USE_TOUCH_UI_LAYOUT {
-        // ~1/40 of the window width gives ~22 px on a 900 logical-px phone.
-        // Clamped so it never goes too tiny on narrow viewports or too large
-        // on landscape tablets.
-        (window_width / 40.0).clamp(16.0, 30.0)
+        // Seven word-labels ("Menu","Undo","Pause","Help","Hint","Mode","New")
+        // must share one row. The widest characters are in FiraMono (a
+        // monospace whose advance is ~0.62 of the font size). On a 900
+        // logical-px phone the row budget after bar padding (2*12) and six
+        // 4 px column gaps is ~852 px for ~28 label chars + 7*2*3 px button
+        // padding. Solving 28*0.62*size + 42 <= 852 gives size <= ~46, so the
+        // labels are advance-bound only on very narrow viewports; the real
+        // constraint is legibility, not fit. ~1/60 of the width yields ~15 px
+        // at 900 px — comfortably one row with margin to spare — clamped so it
+        // never drops below the 12 px legibility floor or grows past 18 px on
+        // landscape tablets where it would crowd the row again.
+        (window_width / 60.0).clamp(12.0, 18.0)
     } else {
         TYPE_BODY
     }
@@ -2578,9 +2601,14 @@ fn action_bar_font_size(window_width: f32) -> f32 {
 
 fn action_button_metrics() -> (UiRect, Val, Val) {
     if USE_TOUCH_UI_LAYOUT {
+        // Tight 3 px horizontal padding (down from 4) trims 14 px off the row
+        // total across 7 buttons, and a 44 px min_width (down from 52) lets the
+        // shortest labels ("New", "Help") shrink to their text rather than
+        // padding the row out past the 900 logical-px viewport. min_height
+        // stays at 44 px to preserve the comfortable touch target.
         (
-            UiRect::axes(Val::Px(4.0), Val::Px(4.0)),
-            Val::Px(52.0),
+            UiRect::axes(Val::Px(3.0), Val::Px(4.0)),
+            Val::Px(44.0),
             Val::Px(44.0),
         )
     } else {

solitaire_engine/src/input_plugin.rs

@@ -26,7 +26,7 @@ use bevy::prelude::*;
 use bevy::window::PrimaryWindow;
 #[cfg(not(target_os = "android"))]
 use bevy::window::{MonitorSelection, WindowMode};
-use klondike::{Foundation, KlondikePile, Tableau};
+use solitaire_core::{Foundation, KlondikePile, Tableau};
 use solitaire_core::card::{Card, Suit};
 use solitaire_core::game_state::GameState;
 
@@ -1788,7 +1788,7 @@ const _VEC3_REFERENCED: Option<Vec3> = None;
 mod tests {
     use super::*;
     use crate::layout::compute_layout;
-    use klondike::{Foundation, Tableau};
+    use solitaire_core::{Foundation, Tableau};
     use solitaire_core::game_state::{DrawMode, GameState};
 
     fn clear_test_piles(game: &mut GameState) {
@@ -2276,8 +2276,8 @@ mod tests {
         assert_eq!(*count, 1);
     }
 
-    /// `all_hints` must be empty when both stock and waste are empty and no
-    /// pile-to-pile move exists — the game is truly stuck.
+    // `all_hints` must be empty when both stock and waste are empty and no
+    // pile-to-pile move exists — the game is truly stuck.
     // -----------------------------------------------------------------------
     // Drag-rejection return tween — `CardAnimation` replaces the legacy
     // `ShakeAnim` on the dragged cards. The audio cue

solitaire_engine/src/layout.rs

@@ -7,7 +7,7 @@ use std::collections::HashMap;
 
 use bevy::math::Vec2;
 use bevy::prelude::{Resource, SystemSet};
-use klondike::{Foundation, KlondikePile, Tableau};
+use solitaire_core::{Foundation, KlondikePile, Tableau};
 
 /// Schedule labels for layout-related systems so cross-plugin ordering is
 /// explicit instead of relying on Bevy's automatic resource-conflict ordering

solitaire_engine/src/pending_hint.rs

@@ -26,7 +26,7 @@
 
 use bevy::prelude::*;
 use bevy::tasks::{AsyncComputeTaskPool, Task, futures_lite::future};
-use klondike::KlondikePile;
+use solitaire_core::KlondikePile;
 use solitaire_core::game_state::GameState;
 use solitaire_core::solver::{SolverConfig, SolverResult, try_solve_from_state};
 
@@ -186,7 +186,7 @@ mod tests {
     use super::*;
     use crate::events::HintVisualEvent;
     use crate::input_plugin::HintSolverConfig;
-    use klondike::{Foundation, Tableau};
+    use solitaire_core::{Foundation, Tableau};
     use solitaire_core::card::{Card, Rank, Suit};
     use solitaire_core::game_state::{DrawMode, GameState};
 

solitaire_engine/src/radial_menu.rs

@@ -47,7 +47,7 @@ use bevy::input::touch::Touches;
 use bevy::math::Vec2;
 use bevy::prelude::*;
 use bevy::window::PrimaryWindow;
-use klondike::{Foundation, KlondikePile, Tableau};
+use solitaire_core::{Foundation, KlondikePile, Tableau};
 use solitaire_core::card::Card;
 use solitaire_core::game_state::GameState;
 
@@ -1037,7 +1037,7 @@ mod tests {
         let (dest_pile, anchor) = match app.world().resource::<RightClickRadialState>() {
             RightClickRadialState::Active {
                 legal_destinations, ..
-            } => legal_destinations[0].clone(),
+            } => legal_destinations[0],
             _ => panic!("expected Active"),
         };
 

solitaire_engine/src/replay_overlay/format.rs

@@ -1,6 +1,6 @@
 use super::ReplayPlaybackState;
 use chrono::Datelike;
-use klondike::{Foundation, KlondikePile, Tableau};
+use solitaire_core::{Foundation, KlondikePile, Tableau};
 use solitaire_core::card::{Card, Rank, Suit};
 use solitaire_core::game_state::GameState;
 use solitaire_core::klondike_adapter::SavedKlondikePile;

solitaire_engine/src/replay_overlay/tests.rs

@@ -1,6 +1,6 @@
 use super::*;
 use chrono::NaiveDate;
-use klondike::{Foundation, KlondikePile, Tableau};
+use solitaire_core::{Foundation, KlondikePile, Tableau};
 use solitaire_core::card::{Rank, Suit};
 use solitaire_core::game_state::{DrawMode, GameMode};
 use solitaire_core::klondike_adapter::{SavedKlondikePile, SavedTableau};

solitaire_engine/src/replay_overlay/update.rs

@@ -8,7 +8,7 @@ use super::*;
 use crate::layout::LayoutResource;
 use crate::replay_playback::ReplayPlaybackState;
 use crate::resources::GameStateResource;
-use klondike::KlondikePile;
+use solitaire_core::KlondikePile;
 use solitaire_data::ReplayMove;
 
 /// Overwrites the banner label whenever the resource changes — covers the

solitaire_engine/src/replay_playback.rs

@@ -40,7 +40,7 @@
 //! flag is threaded through, no every-callsite gate is added.
 
 use bevy::prelude::*;
-use klondike::KlondikePile;
+use solitaire_core::KlondikePile;
 use solitaire_data::{Replay, ReplayMove};
 
 use crate::events::{DrawRequestEvent, MoveRequestEvent, StateChangedEvent, UndoRequestEvent};
@@ -555,7 +555,7 @@ mod tests {
     use crate::game_plugin::GamePlugin;
     use bevy::time::TimeUpdateStrategy;
     use chrono::NaiveDate;
-    use klondike::{KlondikePile, Tableau};
+    use solitaire_core::{KlondikePile, Tableau};
     use solitaire_core::game_state::{DrawMode, GameMode};
     use solitaire_core::klondike_adapter::{SavedKlondikePile, SavedTableau};
     use std::time::Duration;

solitaire_engine/src/resources.rs

@@ -6,7 +6,7 @@ use std::sync::Arc;
 use bevy::math::Vec2;
 use bevy::prelude::Resource;
 use chrono::{DateTime, Utc};
-use klondike::KlondikePile;
+use solitaire_core::KlondikePile;
 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

@@ -37,7 +37,7 @@
 
 use bevy::input::ButtonInput;
 use bevy::prelude::*;
-use klondike::{Foundation, KlondikePile, Tableau};
+use solitaire_core::{Foundation, KlondikePile, Tableau};
 use solitaire_core::card::Card;
 use solitaire_core::game_state::GameState;
 
@@ -1110,8 +1110,7 @@ mod tests {
         let selected = app
             .world()
             .resource::<SelectionState>()
-            .selected_pile
-            .clone();
+            .selected_pile;
         // The cycle order starts at Waste, but Waste is empty so the next
         // available pile (Tableau(0)) is selected.
         assert_eq!(selected, Some(KlondikePile::Tableau(Tableau::Tableau1)));
@@ -1277,15 +1276,13 @@ mod tests {
         let before = app
             .world()
             .resource::<SelectionState>()
-            .selected_pile
-            .clone();
+            .selected_pile;
         press_key(&mut app, KeyCode::Tab);
         app.update();
         let after = app
             .world()
             .resource::<SelectionState>()
-            .selected_pile
-            .clone();
+            .selected_pile;
 
         assert_eq!(
             before, after,

solitaire_engine/src/sync_plugin.rs

@@ -3,8 +3,8 @@
 //! On startup, the plugin spawns an async pull task on [`AsyncComputeTaskPool`]
 //! that fetches the remote payload from the active [`SyncProvider`]. Once the
 //! task resolves, the merged result is written to disk and the in-world
-//! resources are updated. On app exit, a blocking push sends the current local
-//! state to the backend.
+//! resources are updated. On app exit, a best-effort async push sends the
+//! current local state to the backend without blocking the Bevy main thread.
 //!
 //! The plugin is completely backend-agnostic: the caller (usually
 //! `solitaire_app`) constructs the right [`SyncProvider`] implementation and
@@ -79,8 +79,8 @@ struct PendingReplayUpload(Option<Task<Result<String, SyncError>>>);
 /// - **Update** — polls the task each frame; on completion merges the remote
 ///   payload with local data, persists the result, and updates in-world
 ///   resources.
-/// - **Last** — on [`AppExit`], performs a blocking push of the current local
-///   state to the active backend.
+/// - **Last** — on [`AppExit`], starts a best-effort async push of the current
+///   local state to the active backend without blocking shutdown.
 ///
 /// Construct via [`SyncPlugin::new`], passing any type that implements
 /// [`SyncProvider`].
@@ -272,11 +272,12 @@ fn poll_pull_result(
     }
 }
 
-/// Last-schedule system: pushes the current local state on [`AppExit`].
+/// Last-schedule system: starts a best-effort push of the current local state
+/// on [`AppExit`] without blocking the Bevy main thread.
 ///
-/// A blocking push is acceptable here — ARCHITECTURE.md §4 explicitly notes
-/// that blocking on exit is permitted because the game loop is already
-/// shutting down.
+/// The detached task may be cut short by process teardown, so local atomic
+/// persistence remains the durable source of truth even if the final remote
+/// push does not complete.
 fn push_on_exit(
     mut exit_events: MessageReader<AppExit>,
     provider: Res<SyncProviderResource>,
@@ -291,20 +292,16 @@ fn push_on_exit(
     exit_events.clear();
 
     let payload = build_payload(&stats.0, &achievements.0, &progress.0);
-    let result = rt.0.block_on(provider.0.push(&payload));
-    match result {
-        Ok(_) => {}
-        // `UnsupportedPlatform` is the expected response of
-        // `LocalOnlyProvider`; treat it the same as the pull path does —
-        // no backend configured is not a failure.
-        Err(SyncError::UnsupportedPlatform) => {}
-        Err(e) => {
-            // Log real push failures on exit so they appear in crash/log
-            // reports. We cannot surface them to the UI at this point (game
-            // loop is done).
-            warn!("sync push on exit failed: {e}");
-        }
-    }
+    let provider = provider.0.clone();
+    let rt = rt.0.clone();
+    AsyncComputeTaskPool::get()
+        .spawn(async move {
+            match rt.block_on(provider.push(&payload)) {
+                Ok(_) | Err(SyncError::UnsupportedPlatform) => {}
+                Err(e) => warn!("sync push on exit failed: {e}"),
+            }
+        })
+        .detach();
 }
 
 /// Update-schedule system: on each `GameWonEvent` push the just-completed

solitaire_engine/src/table_plugin.rs

@@ -6,7 +6,7 @@
 
 use bevy::prelude::*;
 use bevy::window::WindowResized;
-use klondike::{Foundation, KlondikePile, Tableau};
+use solitaire_core::{Foundation, KlondikePile, Tableau};
 use solitaire_core::card::Suit;
 
 use crate::events::{HintVisualEvent, StateChangedEvent};
@@ -22,15 +22,28 @@ use crate::ui_theme::TEXT_PRIMARY;
 use solitaire_data::Theme;
 
 /// Default tint applied to every empty-pile marker sprite. Pure white
-/// at 8% alpha — soft enough that the marker reads as a "hint of a
-/// slot" rather than a panel, but visible against every felt
-/// background.
+/// at 15% alpha — soft enough that the marker reads as a "hint of a
+/// slot" rather than a panel, but discernible even against a very dark
+/// felt background under bright ambient light (the old 8% alpha vanished
+/// on a #151515 felt during on-device Android testing).
 ///
 /// Re-exported as the source of truth for `cursor_plugin::MARKER_DEFAULT`,
 /// which used to duplicate the literal alongside a "kept in sync" doc
 /// comment. Pulling both call sites through this const makes drift a
 /// compile error instead of a stale comment.
-pub const PILE_MARKER_DEFAULT_COLOUR: Color = Color::srgba(1.0, 1.0, 1.0, 0.08);
+pub const PILE_MARKER_DEFAULT_COLOUR: Color = Color::srgba(1.0, 1.0, 1.0, 0.15);
+
+/// Tint applied to the thin outline rectangle sitting behind every
+/// empty-pile marker. A slightly brighter white at 28% alpha gives the
+/// slot a defined edge — the standard solitaire "empty pile" affordance —
+/// without competing with real cards. Rendered as a marginally larger
+/// child rectangle one z-step behind the fill, so the fill overlaps it
+/// and only a hairline frame remains visible.
+const PILE_MARKER_OUTLINE_COLOUR: Color = Color::srgba(1.0, 1.0, 1.0, 0.28);
+
+/// Width in logical pixels of the visible outline frame around an empty
+/// pile marker (the outline rect is this much larger on each side).
+const PILE_MARKER_OUTLINE_WIDTH: f32 = 2.0;
 
 /// Holds pre-loaded [`Handle<Image>`]s for the 5 selectable table backgrounds.
 ///
@@ -286,6 +299,22 @@ fn spawn_pile_markers(commands: &mut Commands, layout: &Layout) {
             PileMarker(pile),
         ));
 
+        // Outline frame: a marginally larger rectangle sitting one z-step
+        // behind the fill. The fill overlaps its centre, leaving only a
+        // hairline border visible — a defined slot edge without an extra
+        // asset or 9-slice. Untagged so the `PileMarker` count is unchanged.
+        let outline_size = marker_size + Vec2::splat(PILE_MARKER_OUTLINE_WIDTH * 2.0);
+        entity.with_children(|b| {
+            b.spawn((
+                Sprite {
+                    color: PILE_MARKER_OUTLINE_COLOUR,
+                    custom_size: Some(outline_size),
+                    ..default()
+                },
+                Transform::from_xyz(0.0, 0.0, -0.05),
+            ));
+        });
+
         // Tableau markers show "K" (only a King may start an empty column).
         // Foundation markers show "A" (only an Ace may claim an empty slot).
         // Neither label carries a suit because any suit may start any slot.
@@ -577,7 +606,7 @@ mod tests {
             .world_mut()
             .query::<&PileMarker>()
             .iter(app.world())
-            .map(|m| m.0.clone())
+            .map(|m| m.0)
             .collect();
         types.sort_by_key(|p| format!("{p:?}"));
         types.dedup();
@@ -607,9 +636,9 @@ mod tests {
         let mut visible_piles: Vec<KlondikePile> = Vec::new();
         for (marker, visibility) in q.iter(app.world()) {
             if matches!(visibility, Visibility::Hidden) {
-                hidden_piles.push(marker.0.clone());
+                hidden_piles.push(marker.0);
             } else {
-                visible_piles.push(marker.0.clone());
+                visible_piles.push(marker.0);
             }
         }
 

solitaire_engine/src/touch_selection_plugin.rs

@@ -28,7 +28,7 @@
 
 use bevy::ecs::message::MessageReader;
 use bevy::prelude::*;
-use klondike::KlondikePile;
+use solitaire_core::KlondikePile;
 
 use crate::card_plugin::CardEntity;
 use crate::events::StateChangedEvent;
@@ -192,7 +192,7 @@ fn spawn_touch_highlight(
 #[cfg(test)]
 mod tests {
     use super::*;
-    use klondike::Tableau;
+    use solitaire_core::Tableau;
 
     #[test]
     fn selection_state_default_is_idle() {

solitaire_engine/src/ui_modal.rs

@@ -216,13 +216,14 @@ where
             // modal at `Z_PAUSE` (220) in some scenes.
             GlobalZIndex(z_panel),
             ZIndex(z_panel),
-            // B0004: ModalCard carries Transform (for the scale animation).
-            // Bevy's GlobalTransform hook fires B0004 when a child has
-            // GlobalTransform but the parent does not. Adding Identity
-            // Transform here gives the scrim GlobalTransform so the check
-            // passes. UI layout still uses UiTransform; this has no layout
-            // effect.
+            // B0004: ModalCard carries Transform (for the scale animation)
+            // and visibility-related UI components. Bevy validates that
+            // GlobalTransform / InheritedVisibility parents carry the same
+            // hierarchy components, so the scrim root explicitly carries the
+            // matching identity components. UI layout still uses UiTransform;
+            // this has no layout effect.
             Transform::default(),
+            Visibility::default(),
         ))
         .with_children(|root| {
             root.spawn((