chore(deps-dev): bump @types/node from 20.17.30 to 26.0.0 in /webapp

Bumps [@types/node](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/node) from 20.17.30 to 26.0.0.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/node)

---
updated-dependencies:
- dependency-name: "@types/node"
  dependency-version: 26.0.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

webapp/package-lock.json

@@ -36,7 +36,7 @@
   "devDependencies": {
     "@eslint/eslintrc": "^3",
     "@tailwindcss/postcss": "^4",
-    "@types/node": "^20",
+    "@types/node": "^26",
     "@types/react": "^19",
     "@types/react-dom": "^19",
     "eslint": "^9",