Update dependency groups across the monorepo

[Copilot]

Changelog

New

• Added a changeset for @primer/mcp to cover the published dependency refresh.

Changed

• Dependency refresh by logical group

  • Updated @primer/doc-gen and @primer/mcp dependencies to current releases.
  • Updated private support packages: postcss-preset-primer and rollup-plugin-import-css.
  • Updated root tooling versions used across the workspace.
  • Updated @primer/react and @primer/styled-react dependency sets, keeping React/Vite on the compatible track where newer majors broke builds/types.
  • Updated example app dependencies (codesandbox, nextjs, theming) to current compatible versions.

• Required compatibility fixes for upgraded packages

  • Switched MCP sampling requests to the current SDK shape (temperature instead of nested sampling).
  • Added PostCSS plugin casts in Storybook configs to avoid cross-package PostCSS type conflicts after dependency bumps.
  • Tightened a nullable markdown lint error guard in components-json generation.
  • Adjusted styled-react theme provider children typing to match the installed React/styled-components type graph.
  • Updated PostCSS snapshots where newer plugin versions changed CSS property ordering.
  • Added react-is to styled-components-based examples so Vite production builds resolve correctly.

• Small follow-up cleanup

  • Fixed generated Next.js next-env.d.ts import formatting to satisfy repo lint rules.
  • Marked the Token resize prop type test as an expected error to match the component’s supported prop surface.

Removed

• None.

Rollout strategy

• Patch release
• Minor release
• Major release; if selected, include a written rollout or migration plan
• None; if selected, include a brief description as to why

Testing & Reviewing

Review by dependency group / commit. Most of the code changes are compatibility shims required to keep the upgraded packages buildable and type-safe.

Example of the MCP SDK adjustment:

await server.server.createMessage({
  messages: [
    {
      role: 'user',
      content: {type: 'text', text: prompt},
    },
  ],
  temperature: 0.4,
  maxTokens: 500,
})

Merge checklist

• Added/updated tests
• Added/updated documentation
• Added/updated previews (Storybook)
• Changes are SSR compatible
• Tested in Chrome
• Tested in Firefox
• Tested in Safari
• Tested in Edge
• (GitHub staff only) Integration tests pass at github/github-ui (Learn more about how to run integration tests)

Original prompt

help me update the dependencies on this project. Go through each logical group and updated it to the latest version, create a commit for each one.

Created from Copilot CLI via the copilot delegate command.

[changeset-bot]

🦋 Changeset detected

Latest commit: 72df779

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@primer/mcp	Patch

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