fix: metric range voronoi clip

[c-lamoureux]

Description

When a MetricRange child has hoverPoint: true and its metric values fall outside the y-axis domain (e.g. forecast values on a chart where scaleAxisToFit is false), hovering over the chart caused continuous flickering.

Two fixes:

1. Voronoi y-encoding clamp — getVoronoiYEncoding now clamps metric range seed points to [0, height] using clamp(scale(...), 0, height). An unclamped out-of-domain value (e.g. y = -600) produced a voronoi cell that dominated the entire chart area, causing every mouse movement to trigger a hover → layout recalculation loop.

2. Domain filter on filteredTableForTooltip — getFilteredTooltipData now accepts an optional list of metric range hover metrics and excludes rows where the metric maps outside [0, height] on the y scale. This prevents tooltips and popovers from firing on rows that have no visible representation in the chart.

Related Issue

Motivation and Context

When MetricRange data is outside of the y domain, and scaleAxisToFit: false (the default), those values are not included in the y scale, and the resulting out-of-domain voronoi seeds caused the chart to flicker continuously on hover.

How Has This Been Tested?

• Added a Storybook story (WithHoverPointsOutsideDomain under RSC/MetricRange) with forecast rows whose metric values (5000–9500) far exceed the historical y domain (~200–3738). Manually verified no flickering and no tooltips on the out-of-domain forecast points.
• Added a second story (WithHoverPointsAtDomainBoundary) where the first forecast metric value sits exactly at the top of the y domain (4000). Manually verified that the hover point renders fully and is not clipped.
• Updated unit tests in lineMarkUtils.test.ts to assert the clamped voronoi signal expression.
• Updated unit tests in scatterSpecBuilder.test.ts to assert the domain-check filter expression on filteredTableForTooltip.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• I have signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

🎨 Storybook -> https://opensource.adobe.com/react-spectrum-charts/PR-787

📚 Docs -> https://opensource.adobe.com/react-spectrum-charts/PR-787-docs/