Feat: integrated meta-pixel tracking

[Nandan-9]

Integrates Meta Pixel tracking into the Next.js application using Google Tag Manager (GTM)

What was implemented

1. Added GTM container to the Next.js app
2. Configured Meta Pixel via GTM (Custom HTML tag)
3. Enabled default PageView tracking
4. Verified event flow using Meta Test Events
5. Confirmed tracking works via ngrok (local testing)

Technical details

• GTM script injected using next/script with afterInteractive
• Meta Pixel initialized inside GTM:
  fbq('init', '<PIXEL_ID>');
  fbq('track', 'PageView');
• SPA navigation handled to ensure PageView fires on route changes
• Validation done using:
  • GTM Preview mode
  • Meta Events Manager → Test Events

Testing

• Verified PageView events:
• Fire on initial load
• Fire on route changes
• Are received and processed in Meta Test Events
• Confirmed events via ngrok public URL
• No blocking issues from browser extensions

Important note

Custom events (e.g., Lead, Purchase) are not implemented in this PR.

Reason:

• Event setup requires production-ready Pixel integration and stable domain configuration
• Current validation is done in a local/ngrok environment
• Event mapping will be finalized after deployment to production
  (See attached screenshot for current Meta Events Manager state)

[theamankumarsingh]

Needs rebasing.