Development record

An ATX heading line inside an HTML block ends the cold-reading redactor's span early, so the rest of an excluded section travels. The redactor spans sections by the site section walk (sectionSpan in internal/core/reading/project.go over site.Sections), which reads a column-0 '## Next' as a heading even inside a `<div>` block, while a renderer reads that line as raw HTML. For `## audit notes / SECRET / <div> / ## Next / SECRET-IN-DIV / </div> / ## After / KEPT`, SECRET-IN-DIV travels. The verifier refuses a fence opener inside an HTML block (fenceInHTMLBlock) but has no heading-in-HTML-block refusal, and the redacted text it reads has already lost the `<div>` line. Pre-existing on main; the case-insensitive redaction made it reachable for case-variant headings too.