Submitted query reflected in visible heading or result-count label

When a user submits Italian restaurants and the results page renders without echoing that query anywhere on-screen, the user has no confirmation that their search was understood. They cannot tell whether the page is filtered, whether typos were preserved, or whether they landed on the wrong route. This is a fundamental user-experience failure: the results page must close the feedback loop by reflecting the exact string the user typed, otherwise trust in the search breaks down and the user re-enters the query or bounces.

Read the query from the URL search params and render it in the page heading with the result count. Edit app/listings/results/page.tsx:

const query = searchParams.get('q') ?? ''
return (
  <>
    <h1>Results for "{decodeURIComponent(query)}"</h1>
    <p>{count} listings found</p>
  </>
)

Decode the parameter so characters like %20 render as spaces.