Preconditions and environment

• Magento version 2.4-develop
• When using varnish, x-magento-cache-debug header is always returned (see: https://github.com/magento/magento2/blob/2.4-develop/app/code/Magento/PageCache/etc/varnish7.vcl#L208) so I want to do the same feature for build-in cache.
• It will help debug cache status better on production environment without wasting time switching to develop mode

Steps to reproduce

1. Enable production mode: bin/magento deploy:mode:set production
2. Run: curl -I --location-trusted 'https://magento2.test/' | grep -i x-magento-cache-debug

Expected result

Return x-magento-cache-debug header data

Actual result

No return x-magento-cache-debug header data

Additional information

No response

Release note

No response

Triage and priority

• Severity: S0 - Affects critical data or functionality and leaves users without workaround.
• Severity: S1 - Affects critical data or functionality and forces users to employ a workaround.
• Severity: S2 - Affects non-critical data or functionality and forces users to employ a workaround.
• Severity: S3 - Affects non-critical data or functionality and does not force users to employ a workaround.
• Severity: S4 - Affects aesthetics, professional look and feel, “quality” or “usability”.