fix(admin): set explicit width for product search dropdown in order form

Prevents the search dropdown from shrinking or overflowing unpredictably
in the flex container. Also ensures better alignment.

admin-spa/src/routes/Orders/partials/OrderForm.tsx

@@ -530,6 +530,7 @@ export default function OrderForm({
                       onSearch={setSearchQ}
                       disabled={!itemsEditable}
                       showCheckIndicator={false}
+                      className="w-[200px] md:w-[300px]"
                     />
                   </div>
                 ) : (