Hardcoded undocumented phonehome

There's a hardcoded phone home to Google Analytics placed in the `header.php` that's present on every use of the theme. Of note, this may violate data protection laws in some countries, and should be mentioned in the documentation if no off switch is available

Inspect header.php to locate the hardcoded Google Analytics phone-home behavior and check whether the theme provides an off switch. Confirm the intended resolution with project guidance: the behavior should be removed or made controllable, or its presence and implications should be documented if it cannot be disabled.

索引モデルが issue の本文から書いたものです。