feat: overhaul competence pages, unify brand colors, and polish site integrity

- Rewrote all 5 competence pages (Kabeltiefbau, Bohrtechnik, Glasfaser, Planung, Vermessung) with factual data from references
- Unified brand colors: replaced toxic neon green with brand-aligned teal (#10a379)
- Fixed ReferencesSlider injection in dynamic MDX pages
- Enhanced Footer with icon parity, improved branding placement, and unified hover effects
- Refined Header with 3D micro-animations and improved dropdown visibility
- Fixed localized tracking API (rewrites for /stats/api/send)
- Resolved ReferenceErrors in InteractiveGermanyMap and Header state management
- Cleaned reference titles and truncated metadata in lists

next.config.mjs

@@ -465,6 +465,10 @@ const nextConfig = {
   async rewrites() {
     return {
       beforeFiles: [
+        {
+          source: '/:locale/stats/api/send',
+          destination: '/stats/api/send',
+        },
         {
           source: '/:locale/datasheets/:path*',
           destination: '/api/datasheets/:path*',