Sheet, ErrorBanner, Skeleton and EmptyState (#36)

Co-authored-by: dev_agent <dev_agent@cubecraftlabs.com>
Co-committed-by: dev_agent <dev_agent@cubecraftlabs.com>

web/src/ui/EmptyState.test.tsx

@@ -0,0 +1,27 @@
+import { fireEvent, render, screen } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+import { expectMinHitArea } from '../test/hitArea.ts'
+import { EmptyState } from './EmptyState.tsx'
+
+describe('EmptyState', () => {
+  it('shows a Bagel title and body without an action by default', () => {
+    render(<EmptyState title="Quest log is empty">Swipe Try it on a Side quest to save it here.</EmptyState>)
+    const title = screen.getByRole('heading', { name: 'Quest log is empty' })
+    expect(getComputedStyle(title).fontFamily).toBe('var(--font-heading)')
+    expect(screen.getByText('Swipe Try it on a Side quest to save it here.')).toBeInTheDocument()
+    expect(screen.queryByRole('button')).not.toBeInTheDocument()
+  })
+
+  it('renders the optional primary action and calls its handler', () => {
+    const onClick = vi.fn()
+    render(
+      <EmptyState title="No Regulars yet" action={{ label: 'Add a dinner', onClick }}>
+        Add the dinners you make most.
+      </EmptyState>,
+    )
+    const action = screen.getByRole('button', { name: 'Add a dinner' })
+    expectMinHitArea(action)
+    fireEvent.click(action)
+    expect(onClick).toHaveBeenCalledTimes(1)
+  })
+})