New "Slope" tab colours the filled area and stroke line with an SVG
linearGradient driven by per-point slope data (green→yellow→orange→red→
purple scale). Slope is computed from smoothed elevation + cumulative
distance, reusing the existing raw/10s/20s smoothing controls. The
hover tooltip shows slope % (in slope colour) and elevation. Tab is
enabled only when both elevation and distance data are present; the
X-mode and histogram toggles are hidden for this tab.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Davide Scaini
6faf63c2cd