refactor: extract host config into 'host.nix' files

hosts/eetion/default.nix

@@ -6,16 +6,12 @@
 {
   imports = [
     ./hard.nix
-    ../../modules/ssh
+    ./host.nix
     ../../modules/common
+    ../../modules/ssh
     # ../../modules/uptime-kuma
   ];
 
-  host = {
-    username = "h";
-    name = "eetion";
-  };
-
   ssh = {
     inherit (config.host) username;
     publicHostname = config.host.name;

hosts/eetion/host.nix

@@ -0,0 +1,6 @@
+{
+  host = {
+    username = "h";
+    name = "eetion";
+  };
+}