fix: prevent integrations menu from closing when valves modal is open

When the "Valves" modal is opened from the "Integrations" menu, a click outside the modal would incorrectly close the integrations menu first. This was because the dropdown's outside click handler was still active.

This commit fixes the issue by introducing a `closeOnOutsideClick` prop to the `Dropdown` component. This prop is controlled by the `MessageInput` component, which now disables the outside click handler on the integrations menu when the valves modal is open, and re-enables it when the modal is closed.

src/lib/components/common/Dropdown.svelte

@@ -9,12 +9,15 @@
 	export let show = false;
 	export let side = 'bottom';
 	export let align = 'start';
+	export let closeOnOutsideClick = true;
+
 	const dispatch = createEventDispatcher();
 </script>
 
 <DropdownMenu.Root
 	bind:open={show}
 	closeFocus={false}
+	{closeOnOutsideClick}
 	onOpenChange={(state) => {
 		dispatch('change', state);
 	}}