Render nested Action Text attachment content

[nitrnitr]

What changed

Handle bare <action-text-attachment> elements whose HTML is stored in a content attribute.

HEY can nest this element inside a Trix HTML attachment. Previously, ToMarkdown treated it as a file attachment and rendered 📎 attachment, dropping the embedded text and links.

Unnamed elements with non-empty content are now rendered through the existing bounded embedded-HTML path. Named elements remain file attachments.

Added regression coverage for both the nested HTML case and filename precedence.

Testing

• make check
• make build

[Copilot]

Pull request overview

Renders unnamed nested Action Text attachment HTML through the existing bounded Markdown path while preserving named file attachments.

Changes:

• Added nested attachment-content rendering.
• Added regression and filename-precedence tests.

Tip

If you aren't ready for review, convert to a draft PR.
Click "Convert to draft" or run gh pr ready --undo.
Click "Ready for review" or run gh pr ready to reengage.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
internal/htmlutil/markdown.go	Handles embedded Action Text attachment content.
internal/htmlutil/markdown_test.go	Tests nested HTML and filename precedence.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.