fix: checklist Enter key focuses new item on reopened notes

The addItem() focus logic used positional indexing (inputs[afterIndex+1])
but afterIndex came from the full items[] array while DOM inputs only
render active (unchecked) items. On reopened notes, checked items are
interleaved in the parsed content, causing the index offset to be wrong.

Fix: use data-item-id attribute for targeted querySelector lookup.
Test: reopened note with interleaved checked/unchecked items.

Introduced in e5688c9 (active/done split).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/lib/components/Checklist.svelte

@@ -73,9 +73,12 @@
 		items.splice(afterIndex + 1, 0, newItem);
 		items = [...items];
 		emitChange();
+		// Focus by unique ID — positional indexing breaks when checked items
+		// are interleaved in items[] (e.g. reopened notes) because the DOM
+		// only renders active items as inputs
+		const newId = newItem.id;
 		setTimeout(() => {
-			const inputs = document.querySelectorAll<HTMLInputElement>('[data-testid="checklist-input"]');
-			inputs[afterIndex + 1]?.focus();
+			document.querySelector<HTMLInputElement>(`[data-item-id="${newId}"]`)?.focus();
 		}, 0);
 	}
 
@@ -140,6 +143,7 @@
 					class="flex-1 min-w-0 bg-transparent text-sm outline-none {item.checked ? 'text-[var(--text-muted)] line-through' : 'text-[var(--text)]'}"
 					placeholder="List item"
 					data-testid="checklist-input"
+					data-item-id={item.id}
 				/>
 				<button
 					onclick={() => removeItem(item.id)}

tests/e2e/checklist.spec.ts

@@ -73,6 +73,31 @@ test.describe('Checklist', () => {
 		await expect(page.getByTestId('checklist-input')).toHaveCount(2);
 	});
 
+	test('Scenario: Enter key focuses new item on reopened note with interleaved checked items', async ({ authenticatedPage: page }) => {
+		// Given a saved checklist note with interleaved checked/unchecked items
+		// (this is the state when reopening an existing note — checked items
+		// are scattered in the content, not grouped at the end)
+		await createChecklistNote(page, 'Shopping', ['Milk', 'Eggs', 'Bread', 'Butter']);
+
+		// Reopen and check items 1 and 2 so content becomes interleaved
+		await noteCard(page, 'Shopping').click();
+		await page.getByTestId('checklist-checkbox').nth(0).click(); // Milk → done
+		await page.getByTestId('checklist-checkbox').nth(0).click(); // Eggs (now first active) → done
+		await page.getByTestId('close-editor-btn').click();
+
+		// Reopen — parseChecklist restores interleaved order: [x]Milk, [x]Eggs, [ ]Bread, [ ]Butter
+		await noteCard(page, 'Shopping').click();
+		await expect(page.getByTestId('checklist-input')).toHaveCount(2); // Bread, Butter active
+
+		// When the user presses Enter on the first active item (Bread)
+		await page.getByTestId('checklist-input').first().press('Enter');
+
+		// Then focus moves to the newly created empty item
+		await expect(page.getByTestId('checklist-input')).toHaveCount(3);
+		await expect(page.getByTestId('checklist-input').nth(1)).toBeFocused();
+		await expect(page.getByTestId('checklist-input').nth(1)).toHaveValue('');
+	});
+
 	test('Scenario: Backspace on empty item removes it from the list', async ({ authenticatedPage: page }) => {
 		// Given a checklist with two items where the second is empty
 		await page.getByTestId('new-note-btn').click();