Remove retired Cloudflare app integration from v12 without breaking GTM settings #120

What

The v12 tracker still includes build-time options and an output for the retired Cloudflare app. JavaScript settings used by the official Google Tag Manager tag share that runtime options object. The tracker should keep those settings working and safely skip execution outside a browser.

Why

Remove obsolete integration code without changing existing customer configuration or making server-side evaluation fail.

Notes

Requested scope: target v12, preserve sa_settings and data attributes, remove the old Cloudflare app build, and retain an effective client-side window guard.