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/analytics/ProductEngagementTracker.tsx

@@ -0,0 +1,50 @@
+'use client';
+
+import { useEffect } from 'react';
+import { useAnalytics } from './useAnalytics';
+import { AnalyticsEvents } from './analytics-events';
+
+interface ProductEngagementTrackerProps {
+  productName: string;
+  productSlug: string;
+  categories: string[];
+  sku?: string;
+}
+
+/**
+ * ProductEngagementTracker
+ * Deep analytics for product pages.
+ * Tracks specific view events with full metadata for sales analysis.
+ */
+export default function ProductEngagementTracker({
+  productName,
+  productSlug,
+  categories,
+  sku,
+}: ProductEngagementTrackerProps) {
+  const { trackEvent } = useAnalytics();
+
+  useEffect(() => {
+    // Standardized product view event for "High-Fidelity" sales insights
+    trackEvent(AnalyticsEvents.PRODUCT_VIEW, {
+      product_id: productSlug,
+      product_name: productName,
+      product_sku: sku,
+      product_categories: categories.join(', '),
+      location: 'pdp_standard',
+    });
+
+    // We can also track "Engagement Start" to measure dwell time later
+    const startTime = Date.now();
+
+    return () => {
+      const dwellTime = Math.round((Date.now() - startTime) / 1000);
+      trackEvent('pdp_dwell_time', {
+        product_id: productSlug,
+        seconds: dwellTime,
+      });
+    };
+  }, [productName, productSlug, categories, sku, trackEvent]);
+
+  return null;
+}

components/analytics/ScrollDepthTracker.tsx

@@ -0,0 +1,62 @@
+'use client';
+
+import { useEffect, useRef } from 'react';
+import { usePathname } from 'next/navigation';
+import { useAnalytics } from './useAnalytics';
+import { AnalyticsEvents } from './analytics-events';
+
+/**
+ * ScrollDepthTracker
+ * Tracks user scroll progress across pages.
+ * Fires events at 25%, 50%, 75%, and 100% depth.
+ */
+export default function ScrollDepthTracker() {
+  const pathname = usePathname();
+  const { trackEvent } = useAnalytics();
+  const trackedDepths = useRef<Set<number>>(new Set());
+
+  // Reset tracking when path changes
+  useEffect(() => {
+    trackedDepths.current.clear();
+  }, [pathname]);
+
+  useEffect(() => {
+    const handleScroll = () => {
+      const scrollY = window.scrollY;
+      const windowHeight = window.innerHeight;
+      const documentHeight = document.documentElement.scrollHeight;
+
+      // Calculate how far the user has scrolled in percentage
+      // documentHeight - windowHeight is the total scrollable distance
+      const totalScrollable = documentHeight - windowHeight;
+      if (totalScrollable <= 0) return; // Not scrollable
+
+      const scrollPercentage = Math.round((scrollY / totalScrollable) * 100);
+
+      // We only care about specific milestones
+      const milestones = [25, 50, 75, 100];
+
+      milestones.forEach((milestone) => {
+        if (scrollPercentage >= milestone && !trackedDepths.current.has(milestone)) {
+          trackedDepths.current.add(milestone);
+          trackEvent(AnalyticsEvents.SCROLL_DEPTH, {
+            depth: milestone,
+            path: pathname,
+          });
+        }
+      });
+    };
+
+    // Use passive listener for better performance
+    window.addEventListener('scroll', handleScroll, { passive: true });
+
+    // Initial check (in case page is short or already scrolled)
+    handleScroll();
+
+    return () => {
+      window.removeEventListener('scroll', handleScroll);
+    };
+  }, [pathname, trackEvent]);
+
+  return null;
+}

components/analytics/TrackedButton.tsx

@@ -0,0 +1,34 @@
+'use client';
+
+import React from 'react';
+import { Button, ButtonProps } from '../ui/Button';
+import { useAnalytics } from './useAnalytics';
+import { AnalyticsEvents } from './analytics-events';
+
+interface TrackedButtonProps extends ButtonProps {
+  eventName?: string;
+  eventProperties?: Record<string, any>;
+}
+
+/**
+ * A wrapper around the project's Button component that tracks click events.
+ * Safe to use in server components.
+ */
+export default function TrackedButton({
+  eventName = AnalyticsEvents.BUTTON_CLICK,
+  eventProperties = {},
+  onClick,
+  ...props
+}: TrackedButtonProps) {
+  const { trackEvent } = useAnalytics();
+
+  const handleClick = (e: React.MouseEvent<HTMLButtonElement>) => {
+    trackEvent(eventName, {
+      ...eventProperties,
+      label: typeof props.children === 'string' ? props.children : eventProperties.label,
+    });
+    if (onClick) onClick(e);
+  };
+
+  return <Button {...props} onClick={handleClick} />;
+}

components/analytics/TrackedLink.tsx

@@ -0,0 +1,44 @@
+'use client';
+
+import React from 'react';
+import Link from 'next/link';
+import { useAnalytics } from './useAnalytics';
+import { AnalyticsEvents } from './analytics-events';
+
+interface TrackedLinkProps {
+  href: string;
+  eventName?: string;
+  eventProperties?: Record<string, any>;
+  className?: string;
+  children: React.ReactNode;
+  onClick?: () => void;
+}
+
+/**
+ * A wrapper around next/link that tracks the click event.
+ * Useful for adding tracking to server components.
+ */
+export default function TrackedLink({
+  href,
+  eventName = AnalyticsEvents.LINK_CLICK,
+  eventProperties = {},
+  className,
+  children,
+  onClick,
+}: TrackedLinkProps) {
+  const { trackEvent } = useAnalytics();
+
+  const handleClick = (e: React.MouseEvent) => {
+    trackEvent(eventName, {
+      href,
+      ...eventProperties,
+    });
+    if (onClick) onClick();
+  };
+
+  return (
+    <Link href={href} className={className} onClick={handleClick}>
+      {children}
+    </Link>
+  );
+}

components/analytics/analytics-events.ts

@@ -1,18 +1,18 @@
 /**
  * Analytics Events Utility
- * 
+ *
  * Centralized definitions for common analytics events and their properties.
  * This helps maintain consistency across the application and makes it easier
  * to track meaningful events.
- * 
+ *
  * @example
  * ```tsx
  * import { useAnalytics } from '@/components/analytics/useAnalytics';
  * import { AnalyticsEvents } from '@/components/analytics/analytics-events';
- * 
+ *
  * function ProductPage() {
  *   const { trackEvent } = useAnalytics();
- * 
+ *
  *   const handleAddToCart = (productId: string, productName: string) => {
  *     trackEvent(AnalyticsEvents.PRODUCT_ADD_TO_CART, {
  *       product_id: productId,
@@ -20,7 +20,7 @@
  *       page: 'product-detail'
  *     });
  *   };
- * 
+ *
  *   return <button onClick={() => handleAddToCart('123', 'Cable')}>Add to Cart</button>;
  * }
  * ```
@@ -31,6 +31,7 @@ export const AnalyticsEvents = {
   PAGE_VIEW: 'pageview',
   PAGE_SCROLL: 'page_scroll',
   PAGE_EXIT: 'page_exit',
+  SCROLL_DEPTH: 'scroll_depth',
 
   // User Interaction Events
   BUTTON_CLICK: 'button_click',
@@ -38,6 +39,7 @@ export const AnalyticsEvents = {
   FORM_SUBMIT: 'form_submit',
   FORM_START: 'form_start',
   FORM_ERROR: 'form_error',
+  FORM_FIELD_FOCUS: 'form_field_focus',
 
   // E-commerce Events
   PRODUCT_VIEW: 'product_view',
@@ -46,6 +48,7 @@ export const AnalyticsEvents = {
   PRODUCT_PURCHASE: 'product_purchase',
   PRODUCT_WISHLIST_ADD: 'product_wishlist_add',
   PRODUCT_WISHLIST_REMOVE: 'product_wishlist_remove',
+  PRODUCT_TAB_SWITCH: 'product_tab_switch',
 
   // Search & Filter Events
   SEARCH: 'search',
@@ -71,6 +74,7 @@ export const AnalyticsEvents = {
   TOGGLE_SWITCH: 'toggle_switch',
   ACCORDION_TOGGLE: 'accordion_toggle',
   TAB_SWITCH: 'tab_switch',
+  TOC_CLICK: 'toc_click',
 
   // Error & Performance Events
   ERROR: 'error',