Return true when a line cannot serve as a prose description. Rejects
Markdown structural lines (headings, blockquotes, tables, HTML),
mermaid/chart directives, emoji-banner metadata rows, and the known
Key: value banners that Stage-B agents emit as artefact preamble.
Parameters
line: string
Trimmed line from the aggregated Markdown source
Returns boolean
true when the line is not prose and should be skipped
Return
truewhen a line cannot serve as a prose description. Rejects Markdown structural lines (headings, blockquotes, tables, HTML), mermaid/chart directives, emoji-banner metadata rows, and the knownKey: valuebanners that Stage-B agents emit as artefact preamble.