feat(analytics): implement total transparency suite and SEO metadata standardization

- Added global ScrollDepthTracker (25%, 50%, 75%, 100%)
- Implemented ProductEngagementTracker for deep product analytics
- Added field-level tracking to ContactForm and RequestQuoteForm
- Standardized SEO metadata (canonical, alternates, x-default) across all routes
- Created reusable TrackedLink and TrackedButton components for server components
- Fixed 'useAnalytics' hook error in Footer.tsx by adding 'use client'

app/[locale]/[slug]/page.tsx

@@ -6,6 +6,7 @@ import { Metadata } from 'next';
 import { getPageBySlug, getAllPages } from '@/lib/pages';
 import { mdxComponents } from '@/components/blog/MDXComponents';
 import { SITE_URL } from '@/lib/schema';
+import TrackedLink from '@/components/analytics/TrackedLink';
 
 interface PageProps {
   params: Promise<{
@@ -38,11 +39,11 @@ export async function generateMetadata({ params }: PageProps): Promise<Metadata>
     title: pageData.frontmatter.title,
     description: pageData.frontmatter.excerpt || '',
     alternates: {
-      canonical: `/${locale}/${slug}`,
+      canonical: `${SITE_URL}/${locale}/${slug}`,
       languages: {
-        de: `/de/${slug}`,
-        en: `/en/${slug}`,
-        'x-default': `/en/${slug}`,
+        de: `${SITE_URL}/de/${slug}`,
+        en: `${SITE_URL}/en/${slug}`,
+        'x-default': `${SITE_URL}/en/${slug}`,
       },
     },
     openGraph: {
@@ -110,15 +111,19 @@ export default async function StandardPage({ params }: PageProps) {
             <div className="relative z-10 max-w-2xl">
               <h3 className="text-2xl md:text-3xl font-bold mb-4">{t('needHelp')}</h3>
               <p className="text-lg text-white/70 mb-8">{t('supportTeamAvailable')}</p>
-              <a
+              <TrackedLink
                 href={`/${locale}/contact`}
                 className="inline-flex items-center px-8 py-4 bg-accent text-primary-dark font-bold rounded-full hover:bg-white transition-all duration-300 group/link"
+                eventProperties={{
+                  location: 'generic_page_support_cta',
+                  page_slug: slug,
+                }}
               >
                 {t('contactUs')}
                 <span className="ml-2 transition-transform group-hover/link:translate-x-1">
                   &rarr;
                 </span>
-              </a>
+              </TrackedLink>
             </div>
           </div>
         </div>