revamp: migrate Node.js (Express) backend API quickstart to new content model

[arpit-jn]

Description

Migrates the Node.js (Express) backend API quickstart from the old Recipe/Section multi-file format to the new single index.mdx content model, matching the pattern established by backend/fastify.

What changed:

• Replaced 5 files (_index.mdx, index.mdx, interactive.mdx, 02-using.mdx, 03-troubleshooting.mdx) with a single consolidated index.mdx
• New format includes: mode: wide, AI accordion (defaultOpen), <Steps> component, <Check> checkpoint, <AccordionGroup> troubleshooting, and <Accordion> advanced usage sections
• Updated docs.json navigation from nodejs/interactive to nodejs/index
• Added redirect from /docs/quickstart/backend/nodejs/interactive → /docs/quickstart/backend/nodejs
• Localized versions (fr-ca, ja-jp) left untouched

References

• Reference format: main/docs/quickstart/backend/fastify/index.mdx
• Prior work: revamp(quickstart): improve Node.js Express API quickstart DX #545 (revamped interactive.mdx content used as starting point)

Testing

• Built sample Express API from the documented code — public endpoint returns 200, private endpoint returns 401 without token
• Verified page renders on mint dev at /docs/quickstart/backend/nodejs (HTTP 200)
• Verified old /interactive URL redirects correctly (HTTP 307)

Checklist

• I've read and followed CONTRIBUTING.md.
• I've tested the site build for this change locally.
• I've made appropriate docs updates for any code or config changes.
• I've coordinated with the Product Docs and/or Docs Management team about non-trivial changes.

[mintlify]

Preview deployment for your docs. Learn more about Mintlify Previews.

Project	Status	Preview	Updated (UTC)
auth0	🟢 Ready	View Preview	Apr 21, 2026, 11:35 AM

💡 Tip: Enable Workflows to automatically generate PRs for you.

[github-actions]

Summary

Status	Count
🔍 Total	14
✅ Successful	10
⏳ Timeouts	0
🔀 Redirected	2
👻 Excluded	2
❓ Unknown	0
🚫 Errors	0
⛔ Unsupported	0

Redirects per input

Redirects in main/docs/quickstart/backend/nodejs/index.mdx

• [200] https://docs.npmjs.com/downloading-and-installing-node-js-and-npm | Redirect: Followed 1 redirect resolving to the final status of: OK. Redirects: https://docs.npmjs.com/downloading-and-installing-node-js-and-npm --> https://docs.npmjs.com/downloading-and-installing-node-js-and-npm/
• [200] https://jwt.io/ | Redirect: Followed 1 redirect resolving to the final status of: OK. Redirects: https://jwt.io/ --> https://www.jwt.io/
  Full Github Actions output

[ankita10119]

The CLI tab uses to explain what the command does, while the Dashboard tab uses to remind users to replace placeholder values

A few things to fix here -

1. should be on dashboard tab
2. The placeholder reminder is missing from the CLI tab, even though both tabs show the same .env with YOUR_AUTH0_DOMAIN and YOUR_API_IDENTIFIER, so basically the warning tag should be there for both CLI and dashboard tab, with Warning change to Note
3. The CLI (what the command does) sits after the .env block but describes the command, it should be move to right after

[ankita10119]

Just a small suggestion, instead of showing the full package.json, we could show only the scripts block that needs to be added, since npm install already handles writing the dependencies. Also, if we do want to keep the full file, could we update express-oauth2-jwt-bearer to ^1.8.0 (current version)?