Simpler rounded styling

A consistent rounded prop for Avatar and Badge, plus clearer component documentation.

New features

• Added the padding prop to Container.

Improvements

• Expanded prop documentation and clarified component defaults and accessibility guidance.
• Marked Avatar as a client component.

Bug fixes

• Fixed FloatingContent styling.

Breaking changes

• Replaced the shape prop with rounded on Avatar and Badge. Use rounded for the rounded appearance and rounded={false} for square.

// Before
<Avatar shape="rounded" {...props} />

// After
<Avatar rounded {...props} />

• Removed the default paddingInline of 4 from Container. Pass paddingInline={4} to keep the previous spacing.