feat(engine): replace docked touch bar with floating glass tab bar

Touch layout only (desktop bar unchanged): a floating glass pill
(Undo / Draw / Hint / Pause) plus a detached circular Menu button,
margin above the bottom edge on top of the safe-area inset. Draw is
the persistently expanded accent pill (icon + label); other buttons
are icon-only and slide their label out while pressed, snapping under
reduce-motion. Buttons keep the existing marker components so click
handlers, tooltips, focus ring, and chrome toggle work unchanged.
Icons: None degrades to text-fallback labels (MinimalPlugins tests /
SVG regression), keeping the bar fully usable.

Toast stack clearance now derives from TAB_BAR_CLEARANCE_PX; the
legacy touch bar spawn path and primary-button metrics are removed.

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

solitaire_engine/src/hud_plugin/spawn.rs

@@ -360,6 +360,7 @@ pub(super) fn handle_avatar_button(
 pub(super) fn spawn_action_buttons(
     font_res: Option<Res<FontResource>>,
     windows: Query<&Window>,
+    images: Option<ResMut<Assets<Image>>>,
     mut commands: Commands,
 ) {
     let action_font_size =
@@ -370,9 +371,18 @@ pub(super) fn spawn_action_buttons(
         ..default()
     };
 
-    // Bottom bar: full-width, centered, sits above the gesture-navigation zone.
+    // Touch layout: the floating glass tab bar (pill + circular Menu).
+    // `Assets<Image>` is absent under `MinimalPlugins`; `rasterize_into`
+    // returning `None` switches the bar to its text-fallback form.
+    if USE_TOUCH_UI_LAYOUT {
+        let icons = images.and_then(|mut imgs| TabIcons::rasterize_into(&mut imgs));
+        spawn_glass_tab_bar(&mut commands, &font, icons.as_ref());
+        return;
+    }
+
+    // Desktop bottom bar: full-width, centered, docked to the bottom edge.
     // `SafeAreaAnchoredBottom` applies the correct logical-pixel inset once
-    // Android reports it (frames 1-3); initial value is 0.0.
+    // the platform reports it; initial value is 0.0.
     commands
         .spawn((
             Node {
@@ -400,73 +410,10 @@ pub(super) fn spawn_action_buttons(
             HudActionBar,
         ))
         .with_children(|row| {
-            if USE_TOUCH_UI_LAYOUT {
-                spawn_touch_action_bar(row, &font);
-            } else {
-                spawn_desktop_action_bar(row, &font);
-            }
+            spawn_desktop_action_bar(row, &font);
         });
 }
 
-/// Phase F touch action bar — five buttons, three of them big.
-///
-/// The core gameplay trio (**Undo · Draw · Hint**) gets enlarged
-/// thumb-reach targets; Menu and Pause stay compact at the edges. The
-/// utility actions the desktop bar carries are reachable elsewhere on
-/// touch and are deliberately absent here: Help lives in Menu → System,
-/// mode switching lives on the Home screen (Phase B), and New Game is
-/// Home's hero button. Draw duplicates the stock-pile tap so the most
-/// frequent action of all no longer requires reaching the top half of a
-/// tall folded screen.
-pub(super) fn spawn_touch_action_bar(row: &mut ChildSpawnerCommands, font: &TextFont) {
-    // The trailing `order` argument feeds `Focusable { group: Hud, order }`
-    // so Tab (external keyboard) cycles the bar in visual reading order.
-    spawn_action_button(
-        row,
-        MenuButton,
-        "Menu",
-        None,
-        "Open Home, Stats, Achievements, Profile, Settings, or Leaderboard.",
-        font,
-        0,
-        TEXT_SECONDARY,
-    );
-    spawn_primary_action_button(
-        row,
-        UndoButton,
-        "Undo",
-        "Take back your last move. Hold to keep undoing. Costs points and blocks No Undo.",
-        font,
-        1,
-    );
-    spawn_primary_action_button(
-        row,
-        DrawButton,
-        "Draw",
-        "Draw from the stock — same as tapping the deck.",
-        font,
-        2,
-    );
-    spawn_primary_action_button(
-        row,
-        HintButton,
-        TOUCH_HINT_LABEL,
-        "Highlight a suggested move. Cycles through alternatives on repeat taps.",
-        font,
-        3,
-    );
-    spawn_action_button(
-        row,
-        PauseButton,
-        "Pause",
-        None,
-        "Pause the game and freeze the timer.",
-        font,
-        4,
-        TEXT_SECONDARY,
-    );
-}
-
 /// Desktop action bar — unchanged by Phase F (decision 5: the touch bar
 /// is touch-only). All seven actions, uniform sizing.
 pub(super) fn spawn_desktop_action_bar(row: &mut ChildSpawnerCommands, font: &TextFont) {
@@ -585,44 +532,9 @@ pub(super) fn spawn_action_button<M: Component>(
     );
 }
 
-/// Enlarged variant for the touch bar's core gameplay trio (Phase F):
-/// bigger padding / minimum target and a scaled-up label so Undo, Draw,
-/// and Hint read (and hit) as the primary actions. Hotkey chips are
-/// irrelevant on touch, so the variant takes none.
-pub(super) fn spawn_primary_action_button<M: Component>(
-    row: &mut ChildSpawnerCommands,
-    marker: M,
-    label: &str,
-    tooltip: &'static str,
-    font: &TextFont,
-    order: i32,
-) {
-    let (pad, min_w, min_h) = primary_action_button_metrics();
-    let primary_font = TextFont {
-        font: font.font.clone(),
-        // 1.35× the bar's responsive size, capped so landscape tablets
-        // don't blow the row height out.
-        font_size: (font.font_size * 1.35).min(24.0),
-        ..default()
-    };
-    spawn_action_button_sized(
-        row,
-        marker,
-        label,
-        None,
-        tooltip,
-        &primary_font,
-        order,
-        TEXT_PRIMARY,
-        pad,
-        min_w,
-        min_h,
-    );
-}
-
-/// Shared body of [`spawn_action_button`] / [`spawn_primary_action_button`]
-/// — one place owns the component set so `paint_action_buttons`, tooltips,
-/// and the focus ring treat every bar button identically.
+/// Shared body of [`spawn_action_button`] — one place owns the component
+/// set so `paint_action_buttons`, tooltips, and the focus ring treat every
+/// bar button identically.
 #[allow(clippy::too_many_arguments)]
 fn spawn_action_button_sized<M: Component>(
     row: &mut ChildSpawnerCommands,