产品页不公开价格、只收询价，Product 结构化数据该怎么写才不误导搜索和 AI

{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "304 不锈钢离心泵 CB-25",
  "sku": "CB-25",
  "mpn": "CB-25-SS",
  "image": [
    "https://example.com/img/cb-25-1.jpg",
    "https://example.com/img/cb-25-2.jpg"
  ],
  "description": "304 不锈钢卧式离心泵，流量 25 m³/h，扬程 32 m。价格按配置与订购数量报价，最小起订量 10 台。",
  "brand": { "@type": "Brand", "name": "Example Pumps" },
  "category": "工业泵/离心泵",
  "material": "304 不锈钢",
  "additionalProperty": [
    { "@type": "PropertyValue", "name": "流量", "value": 25, "unitCode": "MQH" },
    { "@type": "PropertyValue", "name": "扬程", "value": 32, "unitCode": "MTR" },
    { "@type": "PropertyValue", "name": "进口口径", "value": 65, "unitCode": "MMT" },
    { "@type": "PropertyValue", "name": "最小起订量", "value": 10, "unitCode": "C62" }
  ]
}

add_action('wp_head', function () {
    if (!is_singular('product')) {
        return;
    }
    $id   = get_queried_object_id();
    $data = [
        '@context'    => 'https://schema.org',
        '@type'       => 'Product',
        'name'        => get_the_title($id),
        'description' => wp_strip_all_tags(get_the_excerpt($id)),
        'image'       => array_values(array_filter([
            get_the_post_thumbnail_url($id, 'full'),
        ])),
        'sku'   => get_post_meta($id, '_sku', true),
        'brand' => [
            '@type' => 'Brand',
            'name'  => get_post_meta($id, '_brand', true),
        ],
        'additionalProperty' => array_map(
            fn($row) => [
                '@type'    => 'PropertyValue',
                'name'     => $row['name'],
                'value'    => $row['value'],
                'unitText' => $row['unit'],
            ],
            (array) get_post_meta($id, '_specs', true)
        ),
    ];

    // 只有后台确实填了价格才写 offers
    $price = get_post_meta($id, '_price', true);
    if (is_numeric($price) && (float) $price > 0) {
        $data['offers'] = [
            '@type'         => 'Offer',
            'price'         => (string) $price,
            'priceCurrency' => get_post_meta($id, '_currency', true) ?: 'CNY',
            'availability'  => 'https://schema.org/InStock',
            'url'           => get_permalink($id),
        ];
    }

    $clean = array_filter($data, static function ($v) {
        return $v !== null && $v !== '' && $v !== [];
    });

    printf(
        '<script type="application/ld+json">%s</script>' . PHP_EOL,
        wp_json_encode($clean, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE)
    );
}, 20);

curl -s "https://example.com/products/cb-25/" -o page.html
python3 - <<'PY'
import re, json
html = open('page.html', encoding='utf-8').read()
blocks = re.findall(r'<script[^>]+application/ld\+json[^>]*>(.*?)</script>', html, re.S)
print(len(blocks), 'JSON-LD blocks')
for b in blocks:
    d = json.loads(b)
    print(d.get('@type'), '| offers:', 'offers' in d, '| rating:', 'aggregateRating' in d)
PY