Add a dedicated acme_ddns TSIG key (scoped to ns1 only) and an acl_acme rule
that limits it to TXT updates at or under _acme-challenge.<zone>. An external
ACME client can now write challenge records via RFC 2136; Knot signs them and
transfers to ns2, which never holds the key.
ns1 (primary) now signs every zone with an ECDSA P-256/SHA-256 policy and
manages the SOA serial itself: zonefile-load = difference-no-serial (with
journal-content = all) plus serial-policy = dateserial let records be edited
without bumping the serial by hand. ns2 needs no change; it transfers the
already-signed zone.
Also point the ns1/ns2 AAAA glue at the public Hetzner IPv6 addresses; they
previously pointed at unroutable ZeroTier mesh ULAs.
- Knot authoritative DNS: ns1 primary, ns2 secondary serving cnx.network,
buildfor.life and cnx.email over TSIG-secured zone transfer (modules/dns)
- Knot listens publicly + over ZeroTier; firewall opens port 53
- Complete clan inventory: name/domain, admin SSH key, control as the
zerotier controller, tor on all nixos machines
- Enable age yubikey/fido2-hmac secret plugins