Look-ahead branch map colors merge rails by the commit they descend to; join curves keep their branch color to the fork; off-page parents render neutral, never a hashed hue for the empty name; drop vector-effect (zoom-variant thickness) for plain 2.5px strokes. Lint now checks color continuity at every cell boundary and stroke uniformity; unit tests pin the dev-line coloring end to end. check-in: 54f1834d26 user: dmestas tags: trunk