[WIP] Add Storybook and Playwright setup for Copilot cloud agent

[Copilot]

Original PR: #6
Triggering comment (#6 (comment)):

@copilot Goal:
Convert the current route-based demo lab iteration into a Storybook-based demo system for GoodWidget.
Update and make the changes in a new pull-request branched out from copilot/feat-route-based-demo-lab-playwright-setup.

Context:
This PR proved that the repo can support:

• local browser demo execution
• Playwright in Copilot cloud agent
• deterministic widget demos
• mock wallet/provider setup
• screenshots, traces, and video artifacts
• stable selectors for automated validation

Do not treat the existing route-based examples/react-web approach as something that must be preserved.
It was a useful test iteration. The new target is Storybook-first.

GoodWidget needs a demo/docs environment because it is:

• a component library
• a design system
• a widget framework
• an ecosystem widget platform where integrators can choose protocol features to expose

The environment should let developers and external contributors:

• browse primitives
• inspect widgets
• play with args/controls
• test token overrides
• test component theme overrides
• test host/integrator themeOverrides
• understand the design-system contract through clear examples
• use generated docs instead of relying only on README guidance
• run visual and interaction checks consistently

Task:
Refactor PR #6 toward Storybook.

Implementation direction:

1. Add Storybook for React + Vite.
2. Prefer a dedicated Storybook package/location, for example:
   • examples/storybook
     or another clean monorepo package if better.
3. Move the useful demo concepts from examples/react-web into Storybook stories.
4. Do not maintain duplicate route-based demo pages.
5. Keep Playwright/cloud-agent compatibility, but point it at Storybook instead of the route app where practical.

Storybook must support:

• component stories
• widget stories
• args/controls
• autodocs
• interaction tests with play functions
• visual/screenshot testing through Playwright or Storybook-compatible test tooling
• deterministic mock wallet/provider stories
• theme/token/brand-kit override exploration

Initial representative stories:

• Card
• GlowCard
• Drawer
• TokenAmount
• ClaimWidget
• Theme override / brand-kit playground

Theme playground requirements:
Create at least one Storybook story or story group where users can switch or experiment with:

• default GoodWalletV2 preset
• token overrides
• component theme overrides
• host themeOverrides-style runtime overrides

The story/docs copy must clearly explain:

• token overrides are broad design-system inputs
• component themes are targeted visual overrides
• host themeOverrides are runtime integrator overrides
• named component parts are API-like and should not be exposed accidentally

Playwright/cloud-agent requirements:

• Update Playwright config so automated tests can target Storybook.
• Keep screenshots enabled.
• Keep traces enabled.
• Keep video-on-failure or equivalent.
• Ensure tests run in Copilot cloud agent.
• Update .github/workflows/copilot-setup-steps.yml if needed.
• Ensure Storybook can run on localhost in the cloud-agent environment.
• Add or update scripts so an agent can run:
  • install/build
  • start Storybook
  • run Storybook smoke/interaction/visual checks

Suggested scripts:

• pnpm storybook
• pnpm build-storybook
• pnpm test:storybook
• optionally keep pnpm test:demo only if still meaningful

Repository cleanup:

• If examples/react-web is no longer the canonical demo surface, update docs to say so.
• Remove route-demo documentation that no longer applies.
• Do not leave misleading docs that describe examples/react-web as the canonical demo lab.
• Reuse mock wallet/provider utilities from PR feat: route-based demo lab + Playwright setup for Copilot cloud agent #6 if useful, but move them to a shared demo/test fixture location so that Storybook can use it.

Documentation requirements:
Update or create docs explaining:

• Storybook is the canonical GoodWidget demo/docs environment
• how to run Storybook locally
• how to run it in Copilot cloud agent
• how to add a new primitive story
• how to add a new widget story
• how to write args/controls
• how to add theme override examples
• how to add interaction tests
• how to generate screenshots/traces/videos
• expectations for outside contributors adding demos

Acceptance criteria:

• Storybook runs locally.
• Storybook builds successfully.
• Representative stories exist.
• Autodocs are enabled and visible.
• Args/controls are useful for at least the representative primitives.
• Theme/brand-kit override playground exists.
• ClaimWidget renders in Storybook with deterministic mock wallet/provider state.
• At least one interaction test exists.
• Automated tests target Storybook and produce useful artifacts.
• Copilot cloud-agent setup works with the new Storybook flow.
• Documentation reflects Storybook as the primary demo system.
• The previous route-based app is removed.

Validation commands:
Run the relevant commands and report results:

• pnpm install
• pnpm build
• pnpm build-storybook
• pnpm test:storybook
• any remaining demo/test commands if kept
• Run playwright and recreate screenshots.

Important:
This should be a Storybook-first conversion of PR #6, not an additive “support both” setup.
Only document if there is a concrete technical reason that Storybook cannot cover a specific flow and why its not included (yet).