Add scatter, range, and horizontal bar charts

[oshtz]

Summary

Adds the missing Cartesian geometries needed for numeric comparisons while preserving existing chart APIs.

• Add ScatterChart and Scatter with numeric axes, dithered points, labels, tooltips, hover, and selection.
• Add RangeChart and Range for horizontal low/value/high intervals with dithered value markers.
• Add opt-in layout=horizontal support to BarChart.
• Preserve the existing vertical layout as the default, including grouped and stacked bars.
• Generalize Cartesian scaling, axes, grid rendering, hit testing, and dither painting for the new geometries.
• Add exports, registry entries, generated registry JSON, documentation, and geometry tests.

Example

<ScatterChart
  data={data}
  config={config}
  xKey=cost
  xDomain={[0, maxCost]}
  yDomain={[0, 1]}
>
  <XAxis />
  <YAxis />
  <Tooltip labelKey=model />
  <Scatter dataKey=score labelKey=model radius={5} />
</ScatterChart>

<RangeChart
  data={data}
  config={config}
  categoryKey=model
  domain={[0, 1]}
>
  <XAxis />
  <YAxis dataKey=model />
  <Tooltip labelKey=model />
  <Range dataKey=mean lowKey=low highKey=high />
</RangeChart>

Horizontal bars use layout=horizontal, category labels on YAxis, and numeric values on XAxis.

Compatibility

Existing BarChart callers remain vertical by default. Existing grouped and stacked behavior is unchanged.

No application-specific UI or SVG export changes are included.

Validation

• npm test — 4 geometry tests passed
• npm run build — generated 8 registry items with 39 file references
• Verified in a temporary Vite consumer at desktop and narrow widths in light and dark themes