solve email template issue in Odoo 17 community in the email, header and footer

a) A general header template should be created/updated. Always shown the branche logo and slogan.

b) There are dynamic buttons in the existing email header. These are correct in the preview with rounded corners at the bottom and general spacing from the label text.
However, only a rectangular field appears for the email recipient and the label text has no spacing from the frame.

The button need to be "moved" from the header to the content in order to always generate the correct link from the respective email template.
-Ticket emails always contain the link to the customer portal current ticket
-Invoice emails always contain the link to the customer portal current invoice
-Order confirmation emails always contain the link to the customer portal current order
-Offer emails always contain the link to the customer portal current offer
.... etc.

The changes must be clearly documented so that I (or the administrator) can easily reproduce/install them on the work server.

c) footer template always need show branch details (ex. Company Name, link to correct pages)