WS-NA: Makes nextjs storybook path explicit

[Isabella-Mitchell]

Resolves JIRA: WS-NA (context here)

Summary

I had to manually delete my build file to get Storybook to work locally. This change would prevent the need to do this manually. (But we can just delete it manually - so this PR might be extra)

Copilot: "Running next build locally copies all source files — including .stories.tsx files — into ws-nextjs-app/build/standalone/ due to the output: 'standalone' Next.js config. The Storybook stories glob was too broad and picked these up, causing webpack to fail because the copied files' relative imports couldn't resolve from inside build/standalone/."

Code changes

• Limits Storybook stories glob to only include pages (automatically exlcuding build)

(I initially tried negation but this didn't work. If we ever add something like ws-nextjs-app/components then we will need to specify this here)

Testing

1. Make a build inside the ws-nextjs-app using a build command, e.g. yarn build:live
2. Run storybook locally using yarn storybook

Useful Links

• Coding Standards
• Repository use guidelines
• Add Links to useful resources related to this PR if applicable.

[Copilot]

Pull request overview

Updates Storybook configuration to avoid picking up copied .stories.tsx files from ws-nextjs-app/build/standalone after running a local Next.js standalone build, which can break Storybook due to unresolved relative imports.

Changes:

• Narrows the Storybook stories glob for ws-nextjs-app from the whole app to only ws-nextjs-app/pages/**, implicitly excluding build output.
• Keeps existing Storybook story discovery for the legacy and src/app areas unchanged.