feat: rejected-cookie cache exclusions for WooCommerce cart

Add wp_recache_rejected_cookies option (defaults: woocommerce_items_in_cart,
wp_woocommerce_session_*, wp-postpass, comment_author_*, wordpress_*) that
bypasses page cache when any listed cookie is present. Both the WP-level
check (wp_recache_should_exclude) and the standalone drop-in apply the
same exact/prefix matching logic. Editing the option regenerates the
drop-in and purges all cache.

includes/Admin/views/settings.php

@@ -52,6 +52,19 @@ $stats = WP_Recache_Admin::get_cache_stats();
                             <p class="description">One URL per line. These pages will not be cached.</p>
                         </td>
                     </tr>
+                    <tr>
+                        <th scope="row">Rejected Cookies</th>
+                        <td>
+                            <textarea name="wp_recache_rejected_cookies" rows="5" cols="50" class="large-text"><?php echo esc_textarea(implode("\n", get_option('wp_recache_rejected_cookies', [
+                                'woocommerce_items_in_cart',
+                                'wp_woocommerce_session_*',
+                                'wp-postpass',
+                                'comment_author_*',
+                                'wordpress_*',
+                            ]))); ?></textarea>
+                            <p class="description">One cookie name per line. Visitors with these cookies bypass the cache. Use <code>*</code> as a suffix to match a prefix (e.g. <code>comment_author_*</code>).</p>
+                        </td>
+                    </tr>
                 </table>
 
                 <h2>Cache Statistics</h2>