build(deps): bump react-dom and @types/react-dom in /frontend

Bumps [react-dom](https://github.com/facebook/react/tree/HEAD/packages/react-dom) and [@types/react-dom](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/react-dom). These dependencies needed to be updated together.

Updates `react-dom` from 19.1.0 to 19.2.6
- [Release notes](https://github.com/facebook/react/releases)
- [Changelog](https://github.com/facebook/react/blob/main/CHANGELOG.md)
- [Commits](https://github.com/facebook/react/commits/v19.2.6/packages/react-dom)

Updates `@types/react-dom` from 19.1.6 to 19.2.3
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/react-dom)

---
updated-dependencies:
- dependency-name: react-dom
  dependency-version: 19.2.6
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: "@types/react-dom"
  dependency-version: 19.2.3
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

frontend/package.json

@@ -54,7 +54,7 @@
     "next-themes": "^0.4.6",
     "react": "^19.2.6",
     "react-day-picker": "^9.14.0",
-    "react-dom": "^19.1.0",
+    "react-dom": "^19.2.6",
     "react-hook-form": "^7.75.0",
     "react-hot-toast": "^2.5.0",
     "react-markdown": "^10.1.0",