feat: V2/V3组件体系与水墨雅致视觉改造

- 新增detail-v2组件库(HeroV2/V3, TrustSectionV2, CTASectionV2等)
- Hero组件水墨雅致改造:浅色宣纸底/深色墨色文字/墨韵纹理
- 方案卡片添加推荐组合徽标(Package图标)
- 独立产品页从V1组件迁移到V2/V3
- 修复why-us-section未使用导入和ESLint引号转义错误

src/components/layout/mobile-menu.tsx

@@ -94,7 +94,7 @@ export function MobileMenu({ className }: MobileMenuProps) {
                         </button>
                         {expandedDropdown === item.dropdownKey && (
                           <ul className="pl-4 space-y-1 mt-1 mb-2" role="list">
-                            {(MEGA_DROPDOWN_DATA[item.dropdownKey] ?? []).map((sub) => (
+                            {(MEGA_DROPDOWN_DATA[item.dropdownKey] ?? []).flatMap(group => group.items).filter(sub => sub.href !== '#').map((sub) => (
                               <li key={sub.id}>
                                 <StaticLink
                                   href={sub.href}