[Tech & Design] Move the single & grouped `vf-details` chevron to the right of the header row

[archibald-ebi]

Summary

Update the single & grouped vf-details treatment so the disclosure chevron appears on the right of the header row.

Background and rationale

The review found that a left-positioned disclosure chevron makes accordion-like vf-details rows too similar to tree structures. This creates ambiguity about the expected behaviour and weakens the distinction between a disclosure group and hierarchical navigation.

Placing the chevron on the right follows the visual convention observed in the reviewed accordion systems and gives the grouped row a clearer accordion-like structure.

User story

As a user viewing a grouped disclosure, I need the state indicator to be positioned consistently with the row's expected behaviour so that I do not confuse it with tree navigation.

Proposed work

• Update the grouped vf-details molecule to place its chevron on the right of the summary/header row.
• Define the closed and open chevron states.
• Keep the full summary row interactive.
• Preserve native disclosure semantics and keyboard behaviour.
• Confirm that wrapped summary text does not collide with the chevron.
• Leave the current single vf-details treatment unchanged unless separately approved.
• Update documentation and design examples.

Acceptance criteria

• The chevron appears on the right side of the header row in all variants.

Out of scope

• Changing the location of indicators in tree or navigation components.
• Introducing a separate vf-accordion component.
• Adding single-open or multi-open logic.