feat(ui-components): add ui-wizard component

[kiennt23]

Summary

New <ui-wizard> Web Component — a multi-step wizard layout composing existing components.

Features

• 2 layouts: horizontal (steps bar below header) and vertical (steps sidebar on left)
• Composes <ui-step-group>, <ui-button>, <ui-separator> internally
• Header: title with layout-appropriate typography (14px horizontal, 20px vertical)
• Steps: slotted <ui-step-group> auto-configured per layout (S/horizontal, M/vertical)
• Content: generic default slot for any form/content
• Footer: Previous/Next buttons — Previous disabled on step 1, Next becomes "Finish" on last step
• current-step attribute drives step progress + button states
• Events: wizard-step-change with detail.step

API

<ui-wizard layout="vertical" title="Wizard Title" current-step="3">
  <ui-step-group slot="steps">
    <ui-step-item label="Account" sublabel="Optional"></ui-step-item>
    <ui-step-item label="Profile" sublabel="Optional"></ui-step-item>
    <ui-step-item label="Contact" sublabel="Optional"></ui-step-item>
  </ui-step-group>
  <div>Step content goes here</div>
</ui-wizard>

Testing

• 3460 unit tests (43 new)
• 4 Storybook stories (horizontal, vertical, first step, last step)
• 56 Playwright visual regression tests (1 new)

Files

• packages/ui-components/src/components/ui-wizard.ts
• packages/ui-components/src/components/ui-wizard.test.ts
• packages/ui-components/src/stories/ui-wizard.stories.ts
• packages/ui-components/src/index.ts — barrel exports
• apps/catalog/src/pages/wizard.ts — catalog page