Add Storybook deployment to CI

[haljac]

Problem

Storybook is built in CI (build-storybook) but the output is not deployed anywhere. There is no shared, browsable component library for the team. The @chromatic-com/storybook addon is installed but not configured for deployment or visual regression testing.

Scope of Work

Option A: Deploy via Chromatic (recommended)

• The @chromatic-com/storybook addon is already installed
• Add a Chromatic step to CI using chromaui/action
• Requires a CHROMATIC_PROJECT_TOKEN secret
• Provides visual regression testing out of the box

Option B: Deploy to GitHub Pages

• Build Storybook, upload as artifact, deploy to a /storybook path on GitHub Pages
• No visual regression, but zero cost

Regardless of option:

• Storybook should be deployed on every push to main
• PR builds should get a preview link (Chromatic provides this automatically)

Acceptance Criteria

• Storybook is deployed and accessible at a stable URL
• Deployment happens automatically on push to main
• PR builds include a Storybook preview (Chromatic) or artifact link
• Visual regression testing is enabled (if using Chromatic)
• README links to the deployed Storybook