carriedSectionsFrom() decided whether a ## Usage section was generated by matching
its first line against a list of historical opener phrases — so a hand-written
Usage section that happened to open that way was classified as generated and
silently deleted on regeneration. Ownership is now purely set membership: a
section is generated iff its heading is one the template emits, and ambiguous
'usage' is no longer in that set (the template never emits it), so any ## Usage is
carried. Exported carriedSectionsFrom behind an entrypoint guard and added two
executable preservation fixtures. Flagged by Magi (#5).
ukimsanov
d373c3f4a0