Add storefront component migration: cards, badges, progress bars, animations, and React wrapper package

Major feature migration from dt-shopify-storefront into the design system:

- Card system: per-card color modes (normal/emphasis/warning/success/other),
  progress bars, full-bleed card body (card-body-flush), image bevel clip-paths,
  and visible structural borders at bevel corners
- Badge system: dt-card-badge with position-aware offsets for cards vs media frames
- Media frames: dt-bevel-media with inner surface fill, image clipping, and
  "MISSING MEDIA" placeholder for empty containers
- Interactive bevel buttons: dt-btn with hover/selected states and pulse animation
- Menu items: dt-menu-item with active states and level indentation
- Animations: scale-in, fade-in, slide-up, pulse, ping, spin keyframes
- Feature legend: CSS grid for product feature icons with state colors
- Scrollbar styling for DT brand
- New @dangerousthings/react package wrapping web CSS components
- New @dangerousthings/tailwind-preset package
- New @dangerousthings/hex-background package
- Desktop showcase rewritten in React with Tailwind CSS
- Mobile showcase updated with new screens (animations, filters, advanced cards)
- Tokens: added mode color tokens, RGB variants, and selected-state tokens

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

packages/react/src/components/DTBadgeOverlay.tsx

@@ -0,0 +1,50 @@
+/**
+ * DTBadgeOverlay — Absolute-positioned badge container.
+ *
+ * CSS reference: bevels.css .dt-badge-bottom-right, .dt-badge-top-right, etc.
+ */
+
+import type { ReactNode, CSSProperties } from 'react';
+import { cx } from '../utils/cx';
+
+type BadgePosition = 'top-left' | 'top-right' | 'bottom-left' | 'bottom-right';
+
+interface DTBadgeOverlayProps {
+  children: ReactNode;
+  /** Badge position @default 'bottom-right' */
+  position?: BadgePosition;
+  /** Offset from corner in px */
+  offset?: number;
+  className?: string;
+  style?: CSSProperties;
+}
+
+const positionClassMap: Record<BadgePosition, string> = {
+  'top-left': 'dt-badge-top-left',
+  'top-right': 'dt-badge-top-right',
+  'bottom-left': 'dt-badge-overlay',
+  'bottom-right': 'dt-badge-bottom-right',
+};
+
+export function DTBadgeOverlay({
+  children,
+  position = 'bottom-right',
+  offset,
+  className,
+  style,
+}: DTBadgeOverlayProps) {
+  const offsetStyle: CSSProperties = offset
+    ? {
+        ...(position.includes('top') ? { top: `${offset}px` } : { bottom: `${offset}px` }),
+        ...(position.includes('left') ? { left: `${offset}px` } : { right: `${offset}px` }),
+      }
+    : {};
+
+  return (
+    <div
+      className={cx(positionClassMap[position], className)}
+      style={{ ...offsetStyle, ...style }}>
+      {children}
+    </div>
+  );
+}