DataViews: Add scrollY layout option for table views

[dilirity]

What?

Adds a new scrollY layout option to the DataViews table and pickerTable view types.

CleanShot.2026-03-04.at.11.12.16.mp4

Why?

Currently, the entire DataViews wrapper scrolls as one unit. In some use cases (e.g. dense admin tables), it's desirable to keep the view actions and filters pinned at the top while only the table body scrolls vertically. Additionally, the horizontal scroll needs to be handled by the correct container so the sticky actions column shows its border only when overlapping content.

How?

• Adds scrollY?: 'wrapper' | 'table' to the ViewTable and ViewPickerTable layout types. Defaults to 'wrapper' (current behavior).
• When scrollY is 'table', the wrapper disables vertical overflow (overflow-y: hidden) and the table is wrapped in an inner scroll container that handles both vertical and horizontal scrolling.
• A new scrollContainerRef is threaded through DataViewsContext so the table component can expose the inner scroll element to the parent for infinite scroll support and horizontal scroll-end detection.
• The infinite scroll listener in both DataViews and DataViewsPicker attaches to the correct scroll container based on the mode.
• useIsHorizontalScrollEnd receives the appropriate ref so the actions column border logic works with either scroll mode.

Testing Instructions

1. Use a DataViews table with view.layout.scrollY set to 'table'.
2. Verify filters and view actions stay fixed while the table body scrolls vertically.
3. Scroll horizontally and confirm the actions column shows a left border when overlapping content, and no border when scrolled fully right.
4. Test with scrollY unset or set to 'wrapper' to confirm default behavior is unchanged.
5. If using infinite scroll, verify it triggers correctly in both modes.

Testing Instructions for Keyboard

1. Storybook for DataViews -> Layout Table has been updated to include a new option - scrollY. Switch to wrapper to see the original scroll behavior, or table to see the new scroll behavior:

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[dilirity]

Closing as not needed.