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'

components/ContactForm.tsx

@@ -5,11 +5,30 @@ import { useTranslations } from 'next-intl';
 import { Button, Heading, Card, Input, Textarea, Label } from '@/components/ui';
 import { sendContactFormAction } from '@/app/actions/contact';
 import { useAnalytics } from '@/components/analytics/useAnalytics';
+import { AnalyticsEvents } from '@/components/analytics/analytics-events';
 
 export default function ContactForm() {
   const t = useTranslations('Contact');
   const { trackEvent } = useAnalytics();
   const [status, setStatus] = useState<'idle' | 'submitting' | 'success' | 'error'>('idle');
+  const [hasStarted, setHasStarted] = useState(false);
+
+  const handleFocus = (fieldId: string) => {
+    // Initial form start
+    if (!hasStarted) {
+      setHasStarted(true);
+      trackEvent(AnalyticsEvents.FORM_START, {
+        form_id: 'contact_form',
+        form_name: 'Contact',
+      });
+    }
+
+    // Field-level transparency
+    trackEvent(AnalyticsEvents.FORM_FIELD_FOCUS, {
+      form_id: 'contact_form',
+      field_id: fieldId,
+    });
+  };
 
   async function handleSubmit(e: React.FormEvent<HTMLFormElement>) {
     e.preventDefault();
@@ -29,10 +48,18 @@ export default function ContactForm() {
         (e.target as HTMLFormElement).reset();
       } else {
         console.error('Contact form submission failed:', { email, error: result.error });
+        trackEvent(AnalyticsEvents.FORM_ERROR, {
+          form_id: 'contact_form',
+          error: result.error || 'submission_failed',
+        });
         setStatus('error');
       }
     } catch (error) {
       console.error('Contact form submission error:', { email, error });
+      trackEvent(AnalyticsEvents.FORM_ERROR, {
+        form_id: 'contact_form',
+        error: (error as Error).message || 'unexpected_error',
+      });
       setStatus('error');
     }
   }
@@ -112,7 +139,7 @@ export default function ContactForm() {
             name="name"
             autoComplete="name"
             enterKeyHint="next"
-            placeholder={t('form.namePlaceholder')}
+            onFocus={() => handleFocus('name')}
             required
           />
         </div>
@@ -126,6 +153,7 @@ export default function ContactForm() {
             inputMode="email"
             enterKeyHint="next"
             placeholder={t('form.emailPlaceholder')}
+            onFocus={() => handleFocus('email')}
             required
           />
         </div>
@@ -137,6 +165,7 @@ export default function ContactForm() {
             rows={4}
             enterKeyHint="send"
             placeholder={t('form.messagePlaceholder')}
+            onFocus={() => handleFocus('message')}
             required
           />
         </div>