Add Apache Superset & Preset as SQL client application

[rusackas]

Summary

• Add a new SQL client application page for Apache Superset and Preset (sql-client-apps-superset.md)
• Document the elasticsearch-dbapi SQLAlchemy dialect (originally developed and contributed by Preset) as the driver for connecting Superset/Preset to Elasticsearch via the SQL REST API
• Cover connection string formats for username/password auth, API key auth, and Elastic Cloud
• Include optional driver parameters (fetch_size, time_zone, http_compress, timeout) and known limitations
• Update the SQL client applications index page to mention the REST interface alongside JDBC and ODBC
• Register the new page in toc.yml

Test plan

• docs-builder builds with 0 errors and 0 warnings (50 pre-existing hints unchanged)
• Verified the rendered page locally via docs-builder serve at localhost:3000
• Elastic docs team review for style and accuracy

🤖 Generated with Claude Code

[cla-checker-service]

💚 CLA has been signed

[github-actions]

🔍 Preview links for changed docs

• docs/reference/query-languages/sql/sql-client-apps-superset.md
• docs/reference/query-languages/sql/sql-client-apps.md

[github-actions]

ℹ️ Important: Docs version tagging

👋 Thanks for updating the docs! Just a friendly reminder that our docs are now cumulative. This means all 9.x versions are documented on the same page and published off of the main branch, instead of creating separate pages for each minor version.

We use applies_to tags to mark version-specific features and changes.

Expand for a quick overview

When to use applies_to tags:

✅ At the page level to indicate which products/deployments the content applies to (mandatory)
✅ When features change state (e.g. preview, ga) in a specific version
✅ When availability differs across deployments and environments

What NOT to do:

❌ Don't remove or replace information that applies to an older version
❌ Don't add new information that applies to a specific version without an applies_to tag
❌ Don't forget that applies_to tags can be used at the page, section, and inline level

🤔 Need help?

• Check out the cumulative docs guidelines
• Reach out in the #docs Slack channel

[rusackas]

Agreement signed! :D

Also, happy to speak to the right DevRel/Sales/Marketing folks about taking any next steps in partnership discussions. Would love to do logo/link exchange on our respective Preset/Elasticsearch partner pages.

[elasticsearchmachine]

Pinging @elastic/core-docs (Team:Docs)