fix(ui): destructure {item} from POST /api/queue response

submitUrl() was using the full {duplicate, item} response object
as the queue item, causing 'Cannot read properties of undefined
(reading length)' crash when rendering phases in RecipeSheet/
TimelineRow.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/routes/+page.svelte

@@ -130,7 +130,7 @@
 				const err = await response.json();
 				throw new Error(err.message || 'Failed to enqueue URL');
 			}
-			const queueItem = await response.json();
+			const { item: queueItem } = await response.json();
 			// Item will arrive via SSE, but add immediately for UX
 			items = [queueItem, ...items];
 			screen = 'home';