feat(replay): HC-mode coverage for keybind-footer top border

Tag the footer's border-carrying Node with
`HighContrastBorder::with_default(BORDER_SUBTLE)` so the existing
`apply_high_contrast_borders` system bumps the 1 px top border
from `BORDER_SUBTLE` (#505050) to `BORDER_SUBTLE_HC` (#a0a0a0)
when `Settings::high_contrast_mode` is on.

Without this the footer reads as floating loose under HC because
the border that visually anchors it to the labels row above is
near-invisible at #505050 against the elevated banner background.

The footer's text colours (`TEXT_SECONDARY` on both the
mode-line and the hint) don't need an HC bump — `TEXT_SECONDARY`
is already at `#a0a0a0`, the same luminance as `BORDER_SUBTLE_HC`.
There's no `TEXT_SECONDARY_HC` constant in the palette because
secondary text is already at HC-border level by design.

The notch labels also use `TEXT_SECONDARY` and inherit the same
"already HC-bright" property — no marker needed there either.

The 1 px scrub track, notch ticks, and WIN MOVE marker render
via `BackgroundColor` (not `BorderColor`) so the
`HighContrastBorder` marker doesn't apply. HC coverage for those
decorative pieces would need a custom settings-aware paint
system (precedent: `radial_rim_outline` in `radial_menu`) and is
deferred to a follow-up commit.

1 new test pinning the marker on spawn. 1243 → 1244. Clippy clean.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

solitaire_engine/src/replay_overlay.rs

@@ -35,8 +35,9 @@ use crate::replay_playback::{
 use solitaire_data::ReplayMove;
 use crate::ui_modal::{spawn_modal_button, ButtonVariant};
 use crate::ui_theme::{
-    ACCENT_PRIMARY, BG_ELEVATED_HI, BORDER_SUBTLE, STATE_SUCCESS, TEXT_PRIMARY, TEXT_SECONDARY,
+    ACCENT_PRIMARY, BG_ELEVATED_HI, BORDER_SUBTLE, HighContrastBorder, STATE_SUCCESS, TEXT_PRIMARY,
-    TYPE_BODY, TYPE_CAPTION, TYPE_HEADLINE, VAL_SPACE_1, VAL_SPACE_2, VAL_SPACE_4, Z_DROP_OVERLAY,
+    TEXT_SECONDARY, TYPE_BODY, TYPE_CAPTION, TYPE_HEADLINE, VAL_SPACE_1, VAL_SPACE_2, VAL_SPACE_4,
+    Z_DROP_OVERLAY,
 };
 
 // ---------------------------------------------------------------------------
@@ -680,6 +681,14 @@ fn spawn_overlay(
                         ..default()
                     },
                     BorderColor::all(BORDER_SUBTLE),
+                    // Marker for `apply_high_contrast_borders`: bumps
+                    // the 1 px top border from BORDER_SUBTLE (#505050)
+                    // to BORDER_SUBTLE_HC (#a0a0a0) when
+                    // `Settings::high_contrast_mode` is on. Without
+                    // this the footer reads as floating loose under
+                    // HC because the border that visually anchors it
+                    // to the labels row above is near-invisible.
+                    HighContrastBorder::with_default(BORDER_SUBTLE),
                 ))
                 .with_children(|footer| {
                     footer.spawn((
@@ -2008,6 +2017,34 @@ mod tests {
         );
     }
 
+    /// Spawned footer carries `HighContrastBorder` so the existing
+    /// `apply_high_contrast_borders` system bumps the 1 px top
+    /// border under HC mode. Without this the footer reads as
+    /// floating loose under HC.
+    #[test]
+    fn keybind_footer_carries_high_contrast_border_marker() {
+        let mut app = headless_app();
+        set_state(
+            &mut app,
+            ReplayPlaybackState::Playing {
+                replay: synthetic_replay(10),
+                cursor: 0,
+                secs_to_next: 0.5,
+                paused: false,
+            },
+        );
+        app.update();
+
+        let mut q = app
+            .world_mut()
+            .query_filtered::<&HighContrastBorder, With<ReplayOverlayKeybindFooter>>();
+        let marker = q.iter(app.world()).next();
+        assert!(
+            marker.is_some(),
+            "footer must carry HighContrastBorder so `apply_high_contrast_borders` picks it up under HC mode",
+        );
+    }
+
     /// Footer shares the overlay tree's lifecycle — it despawns on
     /// `Playing → Inactive` along with the banner root.
     #[test]