feat(compare): group contrast visibility L1+L2 (v2.1.0)

feat(ui): COMPARE|ANALYSIS|POINTS spatial and camera defaults

chore(render): retire MESH mode; bump to 1.6.0

feat(ribbons): COMPARE|NAV|RIBBONS defaults, fog off, no Points overlay

feat(ui): COMPARE|NAVIGATION|POINTS defaults + full lexicon load

feat(ui): English-only product copy and EN Compare vocab

feat(ui): defaults for ARITHMETIC + ANALYSIS + POINTS from capture

feat(ui): dblclick spatial sliders to restore context defaults