Adapt atomic-facet-manager to acquire facets nested within atomic-popover

[Copilot]

Description

atomic-facet-manager was unable to discover and manage facets nested inside atomic-popover elements because getFacetsInChildren() only checked direct children.

Changes:

• Added isPopover() helper to detect atomic-popover elements
• Modified getFacetsInChildren() in both stencil-facet-common.tsx and facet-common.ts to look inside popover children
• Added 5 unit tests covering nested facet discovery
• Added Storybook story showcasing atomic-facet-manager with facets inside atomic-popover

Usage example:

<atomic-facet-manager>
  <atomic-facet field="author"></atomic-facet>
  <atomic-popover>
    <atomic-facet field="category"></atomic-facet> <!-- Now discovered -->
  </atomic-popover>
</atomic-facet-manager>

Note: Uses find() rather than filter() since atomic-popover enforces a single child facet by design.

Original prompt

Adapt the atomic-facet-manager so that it can acquire a facet nested within atomic-popover

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[louis-bompart]

@copilot add a story in the atomic-facet-manager that showcase its use with atomic-popover.

[Copilot]

@copilot add a story in the atomic-facet-manager that showcase its use with atomic-popover.

Added in commit 0b26e5f. The new story WithPopover (named "With facets inside atomic-popover") demonstrates facets nested inside atomic-popover components within atomic-facet-manager. It can be found in Storybook under Search/FacetManager.