always show parent in breadcrumb navigation

Overall, the breadcrumbs functionality in Builder should be improved.

Specially for deep items, e.g.:


The ellipsis covers the parent, which is ofter the most useful place to go.


I think we should:

1. Not show the current item as a link, but just as text, to avoid confusion.
2. Always show the parent (and add the ellipsis before the parent, if needed).

Potentially:

3. Forward navigation is redundant (as you can always click in on the items shown below and could be removed, to reduce confusion and save a bit of horizontal space.

Start by locating the Builder breadcrumb component and reviewing how it renders deep item paths. Implement the requested navigation behavior: show the parent, place any ellipsis before it, and render the current item as text rather than a link. Treat removing forward navigation as optional, since the issue presents it as a potential follow-up.

Written by the indexing model from the issue text.