feat: add self-hosted cache server

system/dev/dn-server/atticd.nix

@@ -0,0 +1,40 @@
+{
+  config,
+  inputs,
+  system,
+  ...
+}:
+let
+  listenPort = 30098;
+in
+{
+  services.atticd = {
+    enable = true;
+    environmentFile = config.sops.secrets."atticd/secret".path;
+    settings = {
+      listen = "127.0.0.1:${toString listenPort}";
+      jwt = { };
+
+      chunking = {
+        nar-size-threshold = 64 * 1024;
+        min-size = 16 * 1024;
+        avg-size = 64 * 1024;
+        max-size = 256 * 1024;
+      };
+    };
+  };
+
+  services.nginx.virtualHosts."cache.${config.networking.domain}" = {
+    enableACME = true;
+    forceSSL = true;
+    locations."/".proxyPass = "http://127.0.0.1:${toString listenPort}";
+    extraConfig = ''
+      client_max_body_size 10240M;
+    '';
+  };
+
+  environment.systemPackages = with inputs.attic.packages.${system}; [
+    attic-server
+    attic
+  ];
+}