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/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()