[breadcrumbs] Breadcrumbs are hidden on mobile viewport

[CiscoFran10]

Describe the issue

On the Breadcrumbs documentation page, the breadcrumbs component disappears entirely on mobile / small viewports.

From inspecting the implementation, this appears to be caused by the root container using responsive utility classes that hide the component below the sm breakpoint:

export function breadcrumbsVariants({
  size = KUMO_BREADCRUMBS_DEFAULT_VARIANTS.size,
}: KumoBreadcrumbsVariantsProps = {}) {
  return cn(
    "group mr-4 hidden min-w-0 grow items-center sm:flex",
    KUMO_BREADCRUMBS_VARIANTS.size[size].classes,
  );
}

Because of hidden sm:flex, breadcrumbs are never rendered on mobile.

If this behavior is intentional, it would be helpful to document the reasoning and recommended mobile navigation alternatives.
If it is unintentional, this prevents breadcrumbs from being evaluated or used in mobile layouts.

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Expected behavior

One of the following should be true:

• Breadcrumbs remain visible on mobile (possibly with truncation or overflow handling), or
• The docs clearly explain that breadcrumbs are intentionally hidden on mobile and why

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Actual behavior

• Breadcrumbs are completely hidden on mobile screens
• No explanation or guidance is provided in the documentation
• This can be confusing when evaluating the component’s behavior across breakpoints

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Environment

• Package: @cloudflare/kumo
• Component: Breadcrumbs
• Docs site: https://kumo-ui.com/
• Browser: Chrome
• Viewport: Mobile / small screens

[rodrigosdev]

Will look into it! Reproduced it in my phone as well

[mattrothenberg]

Closed by #111