More docs cleanup (#42610)

More docs cleanup (#42610)

* v6: Preserve component radii after bumping $radius to 1rem

Changing the default $radius from .5rem to 1rem doubled every step in the
$radii scale. Remap component and root radius token references down the
scale so their absolute radii stay the same (--radius-5 -> --radius-3,
--radius-7 -> --radius-4, --radius-9 -> --radius-7), and align the
border-radius mixin defaults. The $radii map and .rounded-* utilities are
intentionally left on the new base so opt-in utilities become rounder.

* Revert "v6: Preserve component radii after bumping $radius to 1rem"

This reverts commit 2408a015a34927cd9a590481170d6bea6b867add.

* Add --box-shadow-xs token and .shadow-xs utility

Introduce a smaller box shadow between the existing default and sm sizes,
and expose it through the shadow utilities.

* Docs: collapse page meta dependencies into a count with tooltip

Replace the inline list of dependency links with a single count that
reveals the full list on hover, and drop the now-unused .bd-page-meta
styles.

* Docs: shrink the table of contents as the footer scrolls into view

Add a small docs helper that tracks how far the footer overlaps the
viewport and exposes it as --bd-toc-footer-overlap, so the sticky TOC
height shrinks instead of sliding under the footer.

* Docs: refine example snippet and ad styling

Tokenize the example radius via --bd-example-radius, give resizable
examples an inset preview with a shadow-xs container, and simplify the
Carbon ad wrapper.

* Rebuild dist

Regenerate compiled CSS and JS to pick up the new --box-shadow-xs token
and resync the distributed bundles with source.

* Revert "Rebuild dist"

This reverts commit ecc1f7f8470bcf2bc6bba412e8b5ac622946e7cc.