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/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 {