feat(web): add visual feedback on table row hover and focus

[dgdavid]

Agama tables lacked any visual feedback when users hovered with mouse or navigated rows with the keyboard, making it hard to track which row user is on. PF's built-in solution (isClickable on Tr) was intentionally avoided since it provides the hover highlight out of the box but also adds a pointer cursor and implies the row is clickable, which is not the common use case for Agama tables at this moment (check slightly related commit ae2d3a2 in which the usage of isClickable was discarded).

Thus, a custom CSS rule has been added for covering three interaction cases:

• Mouse hover, standard :hover
• Keyboard navigation, :focus-within, intentionally broad to cover all focusable elements including checkboxes. This ensures keyboard users always know which row they are on. The (small) tradeoff is a residual highlight after checkbox selection that persists until focus moves elsewhere. Since it's not expected mouse users stop suddenly interacting, this is an acceptable edge case where the benefit for keyboard users outweighs the minor annoyance (for a brief amount of time) for mouse users.
• Action menu open, :has(.pf-v6-c-menu-toggle[aria-expanded="true"]), which required fixing a missing isExpanded prop on SimpleDropdown as part of this PR.

The highlight color reuses the same value used for button and menu option hover states for consistency across interactive elements. Defining another color for these elements or a dedicated token for row highlighting is left as a future improvement, though it is not a priority for the team in the mid-term given the amount of other ongoing work.

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Related to

• refactor(web): restore interface for managing DASD from web client #3143
• refactor(web): restore interface for managing iSCSI form web client #3092
• Rethinking storage selectors and other aspects of the storage UI #2459

[joseivanlopez]

Only a typo in changelog.

[joseivanlopez]

LGTM