Alexandria's unbound now only serves LAN clients (192.168.0.0/16) and
returns LAN IPs for service domains.
Created new unbound instance on trantor to serve Tailscale clients
(100.64.0.0/10) and return tailscale IPs for service domains.
Both configurations pull service records from shared/services.nix.
Removed the split-dns.nix module and all service-specific splitDNS.entries
configurations. Service DNS records are now sourced from the centralized
shared/services.nix file instead of being declared individually in each
service configuration.
Created centralized service definitions in shared/services.nix to store
service metadata (domains, IPs, ports) that need to be accessible across
multiple hosts. This replaces the per-service split DNS module approach
with a single source of truth.
Services are now exported through utils.nix for easy access in host configs.
