feat(design): Vibe design optimization — Hero, Bento grids, trust layer, narrative

升级全站体验：首页 Hero 改为产品视觉 + 单一 CTA 转化布局；产品矩阵/服务/方案改
为 Bento 非对称网格（ERP 2x2 大卡 + BI 1x2）；补齐信任层（可验证信号 + 来源标注）
与「问题→方法→结果」章节式叙事；新增 hero-product-visual 与 bento-grid 可复用组件；
统一动效与品牌视觉资产。新增对应单测、UJ-11 用户旅程测试并更新视觉回归基线快照。

src/app/(marketing)/services/services-content-v3.tsx

@@ -195,6 +195,9 @@ function ServicesGridSection({ services }: { services?: Service[] }) {
           {displayServices.map((service, i) => (
             <motion.div
               key={service.id}
+              data-testid={`service-card-${service.id}`}
+              data-featured={i === 0 ? 'true' : 'false'}
+              className={i === 0 ? 'md:col-span-2 bg-white' : 'md:col-span-1 bg-white'}
               initial={{ opacity: 0, y: 30 }}
               whileInView={{ opacity: 1, y: 0 }}
               viewport={{ once: true, margin: '-60px' }}
@@ -202,7 +205,7 @@ function ServicesGridSection({ services }: { services?: Service[] }) {
             >
               <StaticLink
                 href={`/services/${service.id}`}
-                className="group relative block p-8 sm:p-10 md:p-12 transition-all duration-500 hover:bg-bg-secondary hover:shadow-lg hover:-translate-y-1 bg-white border border-transparent hover:border-border-primary"
+                className="group relative block p-8 sm:p-10 md:p-12 transition-all duration-300 hover:bg-bg-secondary hover:shadow-lg hover:-translate-y-1 bg-white border border-transparent hover:border-border-primary after:absolute after:bottom-0 after:left-0 after:h-0.5 after:w-full after:origin-left after:scale-x-0 after:bg-brand after:transition-transform after:duration-300 group-hover:after:scale-x-100"
               >
                 <div className="relative z-10">
                   <h3 className="text-xl sm:text-2xl font-bold text-ink group-hover:text-brand transition-colors duration-300 mb-3">