fix(ui): clean up Dropdown hover class syntax and prop destructuring

[Iqrima]

Summary

Found two minor bugs in apps/web/src/components/ui/components/Dropdown.tsx:

1. Invalid CSS Class Syntax: CHECKBOX_ITEM_BOX_CLASS contained group-hover:not-hover:border-edge-muted which is invalid Tailwind v4 syntax.
2. Duplicate Prop Spreading: DropdownItem passed closeOnSelect={props.closeOnSelect} explicitly without extracting closeOnSelect in splitProps, causing duplicate prop spreading in {...rest}.

Expected behavior

1. Checkbox items inside dropdowns should use valid Tailwind hover variants (group-hover:border-edge-muted).
2. Props in DropdownItem should be cleanly destructured in splitProps to avoid duplicate prop spreading.

Proposed Fix

• Updated CHECKBOX_ITEM_BOX_CLASS to valid Tailwind v4 class syntax.
• Added closeOnSelect to splitProps in DropdownItem.