Task notes - fix opening URLs in new window

[4oo4]

Add the target="_blank" back to the <a> that is stripped out by DOMPurify. Set rel="nofollow noopener noreferrer" to harden against reverse tabnabbing.

I just saw the DCO real name requirement after opening the PR, if this isn't considered trivial feel free to close and have a maintainer recommit.

🤖 AI (if applicable)

• The content of this PR was partly or fully generated using AI.

I used Claude Opus 4.8 (chat, not Claude Code) to help me find why the target was being stripped out, and it suggested the additional rel hardening.

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