fix(modal): clear stale data-closing flag when re-opened mid-close

If the modal is re-enabled within the 150ms close transition the
<dialog> element is still mounted and [open], so the dialogRef watcher
does not re-fire. Clear the leftover data-closing flag directly in
openDialog() so the dialog doesn't remain stuck at opacity 0.

Addresses augmentcode review on #2604.

frontend/src/components/misc/Modal.test.ts

@@ -153,4 +153,36 @@ describe('Modal.vue — open race condition (#2590)', () => {
 
 		wrapper.unmount()
 	})
+
+	it('clears data-closing when re-opened mid-close transition', async () => {
+		// Regression guard: if the user toggles enabled back to true while the
+		// 150ms close transition is still in flight, the <dialog> is still
+		// mounted and [open], so the dialogRef watcher does not re-fire. Make
+		// sure openDialog() clears the leftover data-closing flag itself;
+		// otherwise the dialog stays stuck at opacity 0.
+		const wrapper = mount(Modal, {
+			attachTo: document.body,
+			props: {enabled: true},
+			slots: {default: '<p class="test-body">hi</p>'},
+		})
+		await flushPromises()
+		await nextTick()
+
+		const dialog = document.querySelector('dialog.modal-dialog') as HTMLDialogElement
+		expect(dialog.hasAttribute('open')).toBe(true)
+
+		// Start closing — this sets data-closing and schedules the unmount.
+		await wrapper.setProps({enabled: false})
+		await nextTick()
+		expect(dialog.dataset.closing).toBe('')
+
+		// Re-open well before the 150ms close timer fires.
+		await wrapper.setProps({enabled: true})
+		await nextTick()
+
+		expect(dialog.dataset.closing).toBeUndefined()
+		expect(dialog.hasAttribute('open')).toBe(true)
+
+		wrapper.unmount()
+	})
 })

frontend/src/components/misc/Modal.vue

@@ -97,7 +97,14 @@ function openDialog() {
 	previouslyFocused.value = document.activeElement
 	showDialog.value = true
 	document.body.style.overflow = 'hidden'
-	// The actual `showModal()` call happens in the `watch(dialogRef, …)`
+	// If we're re-opening while the previous close transition is still in
+	// flight the <dialog> is still mounted and [open], so the dialogRef
+	// watcher below won't re-fire. Clear the data-closing flag here so the
+	// dialog doesn't stay stuck at opacity 0.
+	if (dialogRef.value) {
+		delete dialogRef.value.dataset.closing
+	}
+	// The initial `showModal()` call happens in the `watch(dialogRef, …)`
 	// below, which fires the moment Vue mounts the <dialog>. We cannot call
 	// it synchronously here because the element is not in the DOM yet
 	// (v-if="showDialog" only just became true), and we cannot rely on a