fix(engine): fix classic-card corner label colours and HUD-band overlap

card_plugin: AndroidCornerLabel used CARD_FACE_COLOUR (dark ~#1a1a1a) as
the background and BLACK_SUIT_COLOUR (near-white) for clubs/spades text —
both designed for the Terminal theme. On classic PNG cards (white face),
this produced an ugly dark box with invisible black-suit text. Switch the
corner-label background to Color::WHITE and black-suit text to
CARD_FACE_COLOUR (dark ink on white), matching traditional card printing.

layout: HUD_BAND_HEIGHT on Android raised 80 → 112 px. The HUD column has
4 flex tiers plus 3 inter-tier gaps (4 px each) and a SPACE_2 = 8 px top
offset. With empty tiers still occupying gap height in Bevy's flex layout,
the actual rendered HUD could reach ~80 px, overlapping the top card row
by up to one text line. 112 px provides ~28 px clearance in the common
case (Tiers 1 + 3 visible) and remains workable even when Tier 1 wraps.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -355,7 +355,7 @@ Must always be handled explicitly:
 * The gesture/navigation bar at the bottom (≈132px physical on common
   devices) is inside the Bevy viewport; use `SafeAreaInsets.bottom` to
   avoid placing interactive elements in that zone
-* `HUD_BAND_HEIGHT` is 128px on Android (two-row wrap) vs 64px on desktop;
+* `HUD_BAND_HEIGHT` is 112px on Android vs 64px on desktop;
   layout constants are `#[cfg(target_os = "android")]` gated
 * JNI calls must use `attach_current_thread_permanently` — not
   `attach_current_thread` — to avoid detach-on-drop panics