chore(deps): bump react from 18.3.1 to 19.0.0 in /webapp (#1414)

Bumps [react](https://github.com/facebook/react/tree/HEAD/packages/react) from 18.3.1 to 19.0.0.
- [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/v19.0.0/packages/react)

---
updated-dependencies:
- dependency-name: react
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

webapp/package.json

@@ -47,7 +47,7 @@
     "next-themes": "^0.4.3",
     "pino": "^9.3.2",
     "pino-pretty": "^13.0.0",
-    "react": "^18",
+    "react": "^19",
     "react-dom": "^19",
     "react-i18next": "^15.0.0",
     "react-katex": "^3.0.1",