feat(ui): add <CardButton> primitive (UI audit Pattern A fix)

The Button primitive applies `whitespace-nowrap` + a fixed `h-{size}`
because it's tuned for single-line CTAs. Consumers using Button as a
card-shaped picker — title above description, icon next to multi-line
label — hit collapsed/clipped content because of those constraints.

CardButton is the right primitive for that use case:

  - block layout, full-width, left-aligned by default
  - whitespace: normal so multi-line content wraps
  - height: auto so any number of stacked rows works
  - focus-visible ring tied to --bl-focus-ring/--bl-accent (matches Button)
  - disabled opacity + pointer-events
  - selected? prop with subtle inset accent ring (override-able)
  - asChild support via Radix Slot for <Link>/<a> handoff

Bumps @bytelyst/ui to 0.1.6 and re-exports CardButton + CardButtonProps
from the package entry point.

Initial consumers: 5 sites in learning_ai_invt_trdg (StrategyWizard
risk + hours pickers, SimpleView buy + sell plan cards, MyStrategiesTab
diagnostic toggle). See docs/ui/UI_AUDIT.md Pattern A in that repo.

Generated with [Devin](https://cli.devin.ai/docs)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

packages/ui/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@bytelyst/ui",
-  "version": "0.1.5",
+  "version": "0.1.6",
   "type": "module",
   "scripts": {
     "storybook": "storybook dev -p 6006",

packages/ui/src/components/CardButton.tsx

@@ -0,0 +1,71 @@
+import * as React from 'react';
+import { Slot } from '@radix-ui/react-slot';
+import { clsx } from 'clsx';
+
+/**
+ * CardButton — a button-shaped CARD that allows stacked, multi-line content.
+ *
+ * The {@link Button} primitive applies `whitespace-nowrap` and a fixed
+ * `h-{size}` because it's tuned for single-line CTAs (Save, Cancel, Submit).
+ * When you put two stacked spans inside it (e.g. a title + a description),
+ * the second collapses or overflows the fixed height. This is by design —
+ * Button is the wrong primitive for picker/option/action *cards*.
+ *
+ * CardButton drops those constraints and gives you:
+ *   - `display: block` (or flex via `as-child`)
+ *   - `white-space: normal` so text wraps
+ *   - `height: auto` so any number of stacked rows work
+ *   - the same focus-visible ring as Button (keyboard a11y preserved)
+ *   - `disabled` opacity behavior
+ *
+ * Use it whenever a `<Button>` would otherwise wrap a `<div>` or multiple
+ * stacked `<span>`s. See `docs/ui/UI_AUDIT.md` Pattern A in any consumer
+ * repo for the full background.
+ *
+ * @example
+ *   <CardButton onClick={pickRiskStyle}>
+ *     <div className="font-bold">Aggressive</div>
+ *     <div className="text-xs text-muted">Higher risk, higher reward.</div>
+ *   </CardButton>
+ */
+export interface CardButtonProps extends React.ButtonHTMLAttributes<HTMLButtonElement> {
+  selected?: boolean;
+  /** Render as an arbitrary element (e.g. <Link>) via Radix Slot */
+  asChild?: boolean;
+}
+
+export const CardButton = React.forwardRef<HTMLButtonElement, CardButtonProps>(
+  ({ asChild, selected, className, type, ...props }, ref) => {
+    const Comp = asChild ? Slot : 'button';
+
+    const baseStyles = clsx(
+      // Reset native button styling
+      'appearance-none bg-transparent border-0 font-inherit text-inherit',
+      // Layout
+      'block w-full text-left',
+      // Allow stacked / multi-line content (the entire point of this primitive)
+      'whitespace-normal h-auto',
+      // Smooth transitions
+      'transition duration-150',
+      // Focus ring matched to @bytelyst/ui Button
+      'focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-[var(--bl-focus-ring,var(--bl-accent,#5A8CFF))] focus-visible:ring-offset-2 focus-visible:ring-offset-[var(--bl-bg-canvas,#0b0f17)]',
+      // Disabled
+      'disabled:pointer-events-none disabled:opacity-50',
+      // Selected state — consumers can override but a sensible default
+      selected && 'shadow-[inset_0_0_0_2px_var(--bl-accent,#5A8CFF)]'
+    );
+
+    return (
+      <Comp
+        ref={ref}
+        type={asChild ? undefined : (type ?? 'button')}
+        className={clsx(baseStyles, className)}
+        data-card-button
+        data-selected={selected ? 'true' : undefined}
+        {...props}
+      />
+    );
+  }
+);
+
+CardButton.displayName = 'CardButton';

packages/ui/src/index.ts

@@ -1,4 +1,5 @@
 export { Button, type ButtonProps } from './components/Button.js';
+export { CardButton, type CardButtonProps } from './components/CardButton.js';
 export { PageHeader, type PageHeaderProps } from './components/PageHeader.js';
 export { Section, type SectionProps } from './components/Section.js';
 export { Toolbar, type ToolbarProps } from './components/Toolbar.js';