Fix MDX lint URL false positives in prose

[gontzess]

Why

Connector docs can contain ordinary prose such as “To sync (read) data:”. The MDX validator was scanning all text nodes for dangerous URL schemes, so that prose failed as if it were an actual data URL. Connector repos should not need wording-only PRs to work around that false positive.

What this changes

Narrows dangerous URL checks to URL-bearing markdown nodes and JSX attributes. Plain text is no longer scanned as a URL, while links, images, definitions, href/src/action attributes, and encoded dangerous URL schemes remain blocked.

Adds a regression test for the Sentry-style Step content that triggered the failure.

Validation

• npm test --prefix tools/mdx-lint
• patched validator accepts the current baton-sentry docs/connector.mdx
• patched validator still rejects an explicit data: markdown link
• git diff --check

Rollout

After merge, publish the updated reusable workflow ref used by connector repos. They currently call ConductorOne/github-workflows at v4, so v4 must point at this fix before baton-sentry main stops using the old validator.