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/chat/MessageInput/IntegrationsMenu.svelte

@@ -42,6 +42,7 @@
 
 	export let onShowValves: Function;
 	export let onClose: Function;
+	export let closeOnOutsideClick = true;
 
 	let show = false;
 	let tab = '';
@@ -93,6 +94,7 @@
 
 <Dropdown
 	bind:show
+	{closeOnOutsideClick}
 	on:change={(e) => {
 		if (e.detail === false) {
 			onClose();