feat(Folder): add keyboard navigation and accessibility support

[Sarthak-Bhagat2006]

Fixes #988

Changes

• Added keyboard interaction using Enter and Space keys
• Added tabIndex={0} to make the folder focusable
• Added role="button" for semantic accessibility
• Added aria-expanded to communicate open/closed state
• Added dynamic aria-label ("Open folder" / "Close folder")
• Added visible focus indicator for keyboard users

Previously, the Folder component could only be interacted with using a mouse click. Keyboard users were unable to open or close the folder.

This update improves accessibility by allowing users to:

• Navigate to the component using the Tab key
• Toggle the folder using Enter or Space
• Receive proper state information through ARIA attributes
• Clearly identify the focused component

Before

Screen.Recording.2026-06-19.at.12.00.22.AM.mov

• Mouse interaction only
• Not keyboard accessible
• No ARIA semantics

After

Screen.Recording.2026-06-19.at.12.00.59.AM.mov

• Fully keyboard accessible
• Focusable with Tab
• Supports Enter and Space activation
• Includes appropriate ARIA attributes
• Visible focus state