Stacking: a `stack` prop (boolean | 'expand') on the bar + area marks, reusing
$libs/plots `shape-stack`; the frame sums the stacked series for the y-domain.
Entrance animations via an `animate` prop (content domain, reduced-motion-free);
each mark plays its idiomatic motion:
- bars grow from the baseline (new `grow` preset), staggered
- lines draw themselves (new `draw` preset: stroke-dashoffset + pathLength=1)
- area grows up from the baseline (`grow`)
- BarList/BarSegment grow from the left (new `grow-x` preset), staggered
- Pie slices + Radar polygons grow RADIALLY from the chart centre (new `bloom`
preset: scale 0->1 + fade, transform-box: view-box), staggered — so each pie
slice grows out and every radar vertex travels from the origin to its place
- scatter + the area's line edge fade/draw; Sparkline inherits
Four reusable, type-safe, reduced-motion-aware presets added to the eidos motion
engine (grow / draw / grow-x / bloom) + the F7 typegen test. `animate` controls
in every chart demo. Roadmap + MUI X comparison in components/chart/IMPROVEMENTS.md.
Note: generated/base.css is regenerated; it carries one inert `--metrics-*` token
from the metrics recipe that co-lives in the shared generated file.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>