POST /api/contact posted { to, subject, body, replyTo } to ${mailApiUrl}/send,
which the mail service (libreshop/mail src/app.py) does not have, so every
message failed with a 500. It now posts { to_email, subject, message } to
POST /v1/send/message, still to paperwork@muellerprints.de, with the same
subject and text as before. The service sets no Reply-To; the sender's
address stays in the text. A line break in the subject is replaced by a
space, so it cannot start another mail header.
mailApiUrl was read from runtimeConfig without being declared there, so
NUXT_MAIL_API_URL could not set it and the fallback http://mail:2222 was
always used. It is declared now, with that default; mp's compose.yml sets
no NUXT_MAIL_API_URL.
contactMail and mailSendUrl (server/utils/contactMail.ts) are pure and tested.
Refs libretech/mp#71