Feature: Preserve spatial context when selecting data points in EmbeddingView

[piuskern]

Thank you for sharing and maintaining this excellent project - amazing work!

Current behavior
When selecting data points via the Mosaic charts, the EmbeddingView shows only the selected points, and all others disappear. This removes the spatial context, making it difficult to explore the selection within the overall embedding structure.

Desired behavior
Show selected points in a highlight color and keep non-selected points visible in grey or muted tones, similar to the Mosaic charts. Optionally, render selected points on top to ensure they remain clearly visible.

Benefit
This would make it easier to interpret selections in the spatial context and maintain visual continuity during exploration.

I don’t have a specific implementation approach in mind yet, but happy to clarify the use case further if helpful.

[sanghoonio]

Being able to specify specific sizes and fill/stroke for selected points like vg.highlight would be very helpful