The 1 px scrub track and 5 quarter-mark notch ticks paint their
shape via BackgroundColor (not BorderColor — they're tiny
full-bleed Nodes, not borders on wider containers), so the
existing HighContrastBorder marker doesn't apply to them.
Add a parallel primitive in ui_theme: HighContrastBackground
marker carrying default_color, mirroring HighContrastBorder's
shape exactly. Add update_high_contrast_backgrounds system in
settings_plugin alongside update_high_contrast_borders — same
on/off rule (off → marker.default_color, on → BORDER_SUBTLE_HC),
same change-suppression idiom (only mutate when different so
Bevy's change-detection doesn't trigger per-frame repaints).
Tag the scrub track Node and all five notch Nodes with
HighContrastBackground::with_default(BORDER_SUBTLE) so the
existing settings repaint cycle picks them up under HC mode.
The scrub fill (ACCENT_PRIMARY brick-red) and WIN MOVE marker
(STATE_SUCCESS lime-green) don't get the marker — accent and
state colours are already saturated and don't need an HC
luminance variant.
2 new tests: spawn-time marker presence on the track and
cardinality-matches-notch-count on the ticks.
Tests: 1250 → 1252. Clippy clean.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
funman300
d3cb1a51d4