[chaliy]

What changed

Footnote definitions now put their indented body after a blank line. Readers without footnote support can no longer interpret body text as a reference-link destination; readers with footnote support retain the footnote and its text.

Why

The existing nightly render_ir fuzz run found a violation of output-safety invariant S17. A body such as javascript:alert(1) became a link destination when followed by a footnote reference in a reader without footnotes.

Before / After

Before: [^note]: javascript:alert(1) plus [^note] parsed as an unsafe link.
After: the marker and indented body are separated by a blank line; the same reader emits no link.

The new regression failed before the fix and passes afterward for JavaScript, VBScript and file destinations, with assertions for both reader modes. just pre-pr passed. CLI, Python and Node binding smoke tests passed.

Risk

• Low: footnote serialization changes whitespace; Markdown readers with footnote support retain semantics.
• Existing HTML and Markdown expectations were updated. Threat model and changelog describe the safety contract.

Checklist

• Tests added or updated
• Backward compatibility considered