The main dropdown menu component that manages state and positioning.
:id - Required unique identifier for the dropdown menu.:open - Whether the dropdown is initially open. Defaults to false.:use-portal - Whether to render the dropdown in a portal. Defaults to false.:portal-container - CSS selector for the portal container. Defaults to nil.:on-open - Handler for dropdown menu open event.:on-close - Handler for dropdown menu close event.:class - Additional CSS classes.:on-open - Fired when the dropdown menu opens.:on-close - Fired when the dropdown menu closes."open" - Opens the dropdown menu."close" - Closes the dropdown menu."toggle" - Toggles the dropdown menu.