hosts: remove decommissioned media1, ns3, ns4, nixos-test1

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

README.md

@@ -7,7 +7,6 @@ NixOS Flake-based configuration repository for a homelab infrastructure. All hos
 | Host | Role |
 |------|------|
 | `ns1`, `ns2` | Primary/secondary authoritative DNS |
-| `ns3`, `ns4` | Additional DNS servers |
 | `ca` | Internal Certificate Authority |
 | `ha1` | Home Assistant + Zigbee2MQTT + Mosquitto |
 | `http-proxy` | Reverse proxy |
@@ -18,7 +17,6 @@ NixOS Flake-based configuration repository for a homelab infrastructure. All hos
 | `nats1` | NATS messaging |
 | `auth01` | Authentication (LLDAP + Authelia) |
 | `vault01` | OpenBao (Vault) secrets management |
-| `media1` | Media services |
 | `template1`, `template2` | VM templates for cloning new hosts |
 
 ## Directory Structure