fix(docs): tighten onBrokenLinks to throw and fix surfaced broken links (#40102)

Co-authored-by: Claude Code <noreply@anthropic.com>

docs/versioned_docs/version-6.0.0/quickstart.mdx

@@ -15,7 +15,7 @@ Although we recommend using `Docker Compose` for a quick start in a sandbox-type
 environment and for other development-type use cases, **we
 do not recommend this setup for production**. For this purpose please
 refer to our
-[Installing on Kubernetes](/docs/6.0.0/installation/kubernetes/)
+[Installing on Kubernetes](/user-docs/6.0.0/installation/kubernetes/)
 page.
 :::
 
@@ -73,10 +73,10 @@ processes by running Docker Compose `stop` command. By doing so, you can avoid d
 
 From this point on, you can head on to:
 
-- [Create your first Dashboard](/docs/6.0.0/using-superset/creating-your-first-dashboard)
-- [Connect to a Database](/docs/6.0.0/configuration/databases)
-- [Using Docker Compose](/docs/6.0.0/installation/docker-compose)
-- [Configure Superset](/docs/6.0.0/configuration/configuring-superset/)
-- [Installing on Kubernetes](/docs/6.0.0/installation/kubernetes/)
+- [Create your first Dashboard](/user-docs/6.0.0/using-superset/creating-your-first-dashboard)
+- [Connect to a Database](/user-docs/6.0.0/configuration/databases)
+- [Using Docker Compose](/user-docs/6.0.0/installation/docker-compose)
+- [Configure Superset](/user-docs/6.0.0/configuration/configuring-superset/)
+- [Installing on Kubernetes](/user-docs/6.0.0/installation/kubernetes/)
 
 Or just explore our [Documentation](https://superset.apache.org/docs/intro)!