test(mobile): add mobile E2E test suite (53 tests) and fix layout issues

Add comprehensive mobile testing coverage:
- Add chromium-mobile functional test project (iPhone 14, isMobile, hasTouch)
- Add mobile user journey tests (UJ-01/02/04/05/10 mobile variants)
- Add mobile performance baseline tests (FCP/LCP/load time)
- Add mobile accessibility tests (axe-core WCAG 2.1 AA, touch targets,
  form labels, alt text, contrast)
- Update README with progress and new npm scripts

Fix pre-existing issues:
- Fix footer component layout and test assertions
- Fix admin content page sidebar navigation and breadcrumb
- Fix standalone products page metadata and layout
- Fix product detail/service value sections
- Fix contact form layout on mobile
- Fix navigation constants and products data
- Fix layout.tsx CMS config and theme handling
- Fix erp-upgrade content layout

src/components/detail/detail-product-value.tsx

@@ -161,7 +161,7 @@ export function ProductValueSection({ product }: ProductValueSectionProps) {
                   }`}>
                     <Icon className="w-5 h-5" />
                   </div>
-                  <div className="flex-1 min-w-0 pt-1">
+                  <div className="flex-1 min-w-0 mt-3">
                     <FeatureTags text={feature} />
                   </div>
                 </div>

src/components/detail/service-value.tsx

@@ -68,7 +68,7 @@ export function ServiceValueSection({ service }: ServiceValueSectionProps) {
                   }}
                   className="bain-card p-6"
                 >
-                  <div className="flex items-start gap-4">
+                  <div className="flex items-center gap-4">
                     <div className={`shrink-0 w-11 h-11 flex items-center justify-center ${
                       index === 0
                         ? 'bg-brand text-white'
@@ -76,7 +76,7 @@ export function ServiceValueSection({ service }: ServiceValueSectionProps) {
                     }`}>
                       <Icon className="w-5 h-5" />
                     </div>
-                    <p className="text-sm font-medium text-text-secondary leading-relaxed pt-2">
+                    <p className="text-sm font-medium text-text-secondary leading-relaxed">
                       {feature.split('：')[1] || feature}
                     </p>
                   </div>