🎨 Restore from commit 5b041a6 + fix all issues

Restored Header and Footer from best commit (5b041a6) + fixes:

FIXES:
✅ Font size reduced to 16px base (was 18px)
✅ No font scaling on large screens (stays 18px)
✅ Cookie banner: solid bg-gray-900, no transparency
✅ Cookie buttons: solid green/gray colors
✅ Header overlap: Pages have pt-32 padding
✅ Footer: Has privacy/terms links restored

COLORS:
- Green: bg-green-600 (solid)
- Gray: bg-gray-900, bg-gray-700 (solid)
- No transparency anywhere

Build: 11 pages ✅

dist/robots.txt

@@ -1,25 +0,0 @@
-# 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