Close a menu whose trigger a breakpoint hides instead of leaving it open

An app bar's overflow menu is two separate <x-menu> instances trading
places as the width crosses 600px, each display: none where the other
shows. Resizing away from a menu's trigger left its popover in an open
state forever, anchored to a wrapper nobody could see or reach anymore.
A ResizeObserver on the trigger now closes the menu once it has no box
left to render (plan step 36, navigation group).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9

resources/js/menu.js

@@ -141,6 +141,18 @@ const menu = () => ({
             }
         })
 
+        // A breakpoint can hide a trigger out from under an open menu — two overflow menus in an
+        // app bar trading places as the width crosses 600px, one per width, each display: none
+        // where the other shows. Left alone the popover stays open, anchored to nothing.
+        const hides = new ResizeObserver(() => {
+            if (this.isOpen() && this.$refs.trigger.getClientRects().length === 0) {
+                this.close()
+            }
+        })
+
+        hides.observe(this.$refs.trigger)
+        this.listeners.push(() => hides.disconnect())
+
         if (this.$el.hasAttribute('data-md-sheet-at-compact')) {
             this.compact = upTo('medium')