Trim comparison
The rendered form of GET /api/compare - the payload generated
comparison pages consume. Differing features sort first.
S standard
O available
X brochure says not offered
-- no claim made
A dash is not a cross. Subaru's bullet lists
never assert absence, and a feature documented in one brochure simply has no row in
another. Drawing unstated as "not offered" would publish a false negative
about a real vehicle, so it is rendered as a dash and excluded from difference counts
based on availability alone.