feat(responsive,seo): implement responsive design and SEO optimizations

Phase 4: Responsive Design Optimizations
- Increase touch target sizes to min 44px for mobile
- Add touch-manipulation for better touch handling
- Optimize button and input sizes for mobile devices
- Implement responsive font sizing (16px -> 17px -> 18px)

Phase 5: SEO Optimizations
- Enhance metadata with comprehensive Open Graph tags
- Add Twitter Card metadata with images
- Implement Google Search Console verification
- Add structured data (Organization, Website schemas)
- Improve keywords and descriptions

Files modified:
- src/components/ui/button.tsx: Touch-friendly sizes
- src/components/ui/input.tsx: Mobile-optimized inputs
- src/app/globals.css: Responsive font sizing
- src/app/layout.tsx: Enhanced metadata and structured data
- src/components/seo/structured-data.tsx: New structured data components

Impact:
- Better mobile user experience
- Improved search engine visibility
- Enhanced social media sharing
- WCAG 2.1 touch target compliance
- Better SEO performance

src/components/seo/structured-data.tsx

@@ -0,0 +1,80 @@
+export function OrganizationSchema() {
+  const schema = {
+    "@context": "https://schema.org",
+    "@type": "Organization",
+    "name": "四川睿新致远科技有限公司",
+    "alternateName": "诺瓦隆",
+    "url": "https://www.novalon.cn",
+    "logo": "https://www.novalon.cn/logo.svg",
+    "description": "专注于企业数字化转型服务，提供软件开发、云计算、数据分析、信息安全等一站式解决方案",
+    "foundingDate": "2026",
+    "address": {
+      "@type": "PostalAddress",
+      "addressCountry": "CN",
+      "addressLocality": "成都",
+      "addressRegion": "四川省",
+      "streetAddress": "成都市高新区"
+    },
+    "contactPoint": {
+      "@type": "ContactPoint",
+      "telephone": "+86-028-88888888",
+      "contactType": "customer service",
+      "availableLanguage": ["Chinese", "English"]
+    },
+    "sameAs": [
+      "https://www.novalon.cn"
+    ]
+  };
+
+  return (
+    <script
+      type="application/ld+json"
+      dangerouslySetInnerHTML={{ __html: JSON.stringify(schema) }}
+    />
+  );
+}
+
+export function WebsiteSchema() {
+  const schema = {
+    "@context": "https://schema.org",
+    "@type": "WebSite",
+    "name": "四川睿新致远科技有限公司",
+    "url": "https://www.novalon.cn",
+    "potentialAction": {
+      "@type": "SearchAction",
+      "target": "https://www.novalon.cn/search?q={search_term_string}",
+      "query-input": "required name=search_term_string"
+    }
+  };
+
+  return (
+    <script
+      type="application/ld+json"
+      dangerouslySetInnerHTML={{ __html: JSON.stringify(schema) }}
+    />
+  );
+}
+
+export function ServiceSchema() {
+  const schema = {
+    "@context": "https://schema.org",
+    "@type": "Service",
+    "serviceType": "企业数字化转型服务",
+    "provider": {
+      "@type": "Organization",
+      "name": "四川睿新致远科技有限公司"
+    },
+    "description": "提供软件开发、云计算、数据分析、信息安全等一站式数字化转型解决方案",
+    "areaServed": {
+      "@type": "Country",
+      "name": "China"
+    }
+  };
+
+  return (
+    <script
+      type="application/ld+json"
+      dangerouslySetInnerHTML={{ __html: JSON.stringify(schema) }}
+    />
+  );
+}