Add broken-link checking for docs to CI

[EthanThatOneKid]

Context

PR #1362 fixed broken links in custom MDX components, including links in apps/docs/index.mdx and apps/docs/overview/what-is-supermemory.mdx. The immediate link issue was addressed, but the follow-up suggestion to add a preventive CI check remains open.

Proposal

Add a supported Mintlify broken-link check to CI so documentation link regressions are caught before merge. The check should cover apps/docs and fail CI when invalid internal links are detected.

Please confirm the current supported command for the repository's Mintlify version before implementation; mintlify broken-links was the command suggested in #1362.

Reference

• fix(docs): add missing /docs/ prefix to custom component hrefs #1362

Acceptance criteria

• The check runs automatically for documentation changes (or on every pull request, if simpler).
• It validates links under apps/docs.
• CI fails when a broken internal link is introduced.
• The command and any required setup are documented in the workflow or repository docs.

[linear-code]

ENG-1124

[ashish200729]

Hi! I’d like to work on this issue. Is anyone already working on it?

My plan is to confirm the correct Mintlify broken-link command, add it to the GitHub Actions workflow, and make sure CI fails when an invalid internal docs link is introduced.

Please let me know if this approach works, and I’ll start on a PR.