rename nodes and add runner for gitea instance

hosts/sin/secrets.nix

@@ -0,0 +1,13 @@
+{...}: {
+  age.secrets = {
+    # captcha = {
+    #   file = ./secrets/matrix_captcha.age;
+    #   group = "matrix-synapse";
+    #   mode = "770";
+    # };
+    airvpn-params = {
+      file = ./secrets/airvpn_wireguard_key_env.age;
+      mode = "700";
+    };
+  };
+}