🎨 Fix: Add Header and Footer to all pages + standardize colors

MAJOR FIX - Pages were missing Header and Footer components:
✅ Added Header import to all pages
✅ Added Footer import to all pages
✅ Added <Header /> and <Footer /> components
✅ Changed custom colors to standard Tailwind (green-600, gray-*)
✅ Fixed: about-us, services, products, blog pages

COLOR SCHEME:
- primary-600 → green-600 (trust, growth)
- secondary-900 → gray-900 (professional)
- secondary-800 → gray-800
- secondary-600 → gray-600
- secondary-200 → gray-200

All pages now show proper Header navigation and Footer with links!

dist/robots.txt

@@ -0,0 +1,25 @@
+# Robots.txt for dealplustech.co.th
+# https://dealplustech.co.th
+
+User-agent: *
+Allow: /
+
+# Sitemap location
+Sitemap: https://dealplustech.co.th/sitemap.xml
+
+# Disallow admin and private paths
+Disallow: /api/
+Disallow: /_next/
+Disallow: /admin/
+
+# Allow all crawlers access to static assets
+User-agent: Googlebot
+Allow: /images/
+Allow: /fonts/
+
+User-agent: Bingbot
+Allow: /images/
+Allow: /fonts/
+
+# Crawl delay for respectful crawling
+Crawl-delay: 1