fix(deps): group React type packages in Renovate to prevent ERESOLVE

[Copilot]

Renovate runs failed with npm error ERESOLVE ... Found: @types/react@undefined because @types/react and @types/react-dom were bumped in separate PRs. Updating one without the other temporarily breaks the peer constraint peer @types/react@"^19.2.0" from @types/react-dom, halting installs.

Changes

• renovate.json5: Added a packageRules group so react, react-dom, @types/react, and @types/react-dom are updated together atomically.

packageRules: [
  {
    groupName: "react monorepo",
    matchPackageNames: [
      "react",
      "react-dom",
      "@types/react",
      "@types/react-dom",
    ],
  },
],

This keeps the peer dependency satisfied at all times, so the dependency tree resolves cleanly on every Renovate update. No application code or current dependency versions were changed.