manatee: Add schema

The household weekly plan at schema.ppp.pm: its module, certificate,
DNS record, backup and secrets. The link to puppy-tracker is prepared
but commented out until puppy-tracker with the integration feed is
deployed.

hosts/manatee/modules/home-assistant/default.nix

@@ -251,7 +251,7 @@ in
             ];
 
             script = ''
-              SUBDOMAINS="ha komga romm puppy todo"
+              SUBDOMAINS="ha komga romm puppy todo schema"
               INTERFACE="enp3s0"
 
               CURRENT_IP=$(curl -s --fail --interface "$INTERFACE" ifconfig.me)