chore: refactor system modules

system/security/default.nix

@@ -0,0 +1,5 @@
+{
+  imports = [
+    ./sops.nix
+  ];
+}

system/security/sops.nix

@@ -0,0 +1,17 @@
+{
+  sops = {
+    defaultSopsFile = ../../secrets/secrets.yaml;
+    defaultSopsFormat = "yaml";
+    age = {
+      # automatically import user SSH keys as age keys
+      sshKeyPaths = [
+        "/home/phundrak/.ssh/id_ed25519"
+        "/etc/ssh/ssh_host_ed25519_key"
+      ];
+      # this will use an age key that is expected to already be in the filesystem
+      keyFile = "/var/lib/sops-nix/key.txt";
+      # generate a new key if the key specified above does not exist
+      generateKey = true;
+    };
+  };
+}