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/RequestQuoteForm.tsx

@@ -5,6 +5,7 @@ import { useTranslations } from 'next-intl';
 import { Input, Textarea, Button } from '@/components/ui';
 import { sendContactFormAction } from '@/app/actions/contact';
 import { useAnalytics } from '@/components/analytics/useAnalytics';
+import { AnalyticsEvents } from '@/components/analytics/analytics-events';
 
 interface RequestQuoteFormProps {
   productName: string;
@@ -16,6 +17,26 @@ export default function RequestQuoteForm({ productName }: RequestQuoteFormProps)
   const [email, setEmail] = useState('');
   const [request, setRequest] = useState('');
   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: 'quote_request_form',
+        form_name: 'Product Quote Inquiry',
+        product_name: productName,
+      });
+    }
+
+    // Field-level transparency
+    trackEvent(AnalyticsEvents.FORM_FIELD_FOCUS, {
+      form_id: 'quote_request_form',
+      field_id: fieldId,
+      product_name: productName,
+    });
+  };
 
   const handleSubmit = async (e: React.FormEvent) => {
     e.preventDefault();
@@ -39,10 +60,20 @@ export default function RequestQuoteForm({ productName }: RequestQuoteFormProps)
         setEmail('');
         setRequest('');
       } else {
+        trackEvent(AnalyticsEvents.FORM_ERROR, {
+          form_id: 'quote_request_form',
+          product_name: productName,
+          error: result.error || 'submission_failed',
+        });
         setStatus('error');
       }
     } catch (error) {
       console.error('Form submission error:', error);
+      trackEvent(AnalyticsEvents.FORM_ERROR, {
+        form_id: 'quote_request_form',
+        product_name: productName,
+        error: (error as Error).message || 'unexpected_error',
+      });
       setStatus('error');
     }
   };
@@ -131,6 +162,7 @@ export default function RequestQuoteForm({ productName }: RequestQuoteFormProps)
             required
             value={email}
             onChange={(e) => setEmail(e.target.value)}
+            onFocus={() => handleFocus('email')}
             placeholder={t('email')}
             className="h-9 text-xs !mt-0"
           />
@@ -143,6 +175,7 @@ export default function RequestQuoteForm({ productName }: RequestQuoteFormProps)
             rows={3}
             value={request}
             onChange={(e) => setRequest(e.target.value)}
+            onFocus={() => handleFocus('request')}
             placeholder={t('message')}
             className="text-xs !mt-0"
           />