Add known_hosts support in SSH secrets

• Append known_hosts file generation using defined SSH entries
• Change knownHosts type from attribute set to list for simplicity

home/toph/common/core/ssh.nix

@@ -42,6 +42,8 @@ in
           chmod 400 $HOME/.ssh/config
         '';
       };
+
+      ".ssh/known_hosts".text = lib.concatStringsSep "\n" secretsSpec.ssh.knownHosts;
     }
     # Dynamically add all SSH private keys using the existing store paths
     # Ensures the keys have correct permissions and are not symlinks

modules/common/secret-spec.nix

@@ -42,9 +42,9 @@ in
             default = { };
           };
           knownHosts = lib.mkOption {
-            type = lib.types.attrsOf lib.types.str;
-            description = "SSH known hosts entries keyed by hostname";
-            default = { };
+            type = lib.types.listOf lib.types.str;
+            description = "SSH known hosts entries";
+            default = [ ];
           };
         };
       };