Unifies PNG and SVG body-part images behind a single CSS-mask
render path, so both now colorize with a --accent CSS variable.
Accent splits by measurement type: --blue for proportion parts
(chest, shoulders, waist, hips) and --nord8 for muscle parts
(neck, biceps, forearms, thighs, calves). Stats cards gain a
matching 8%-tint fill and accent-colored hover border. History
page header image enlarged. Thigh SVG stroke-width bumped to 11
for better mask legibility.
Cap shell height to viewport minus header so the bottombar stays visible,
allow the stage to scroll internally, and swap the thigh diagram to a
mask-tinted SVG that tracks the text-primary color across themes.
Alexander
