feat: add OpenWebUI service configuration

Introduce a new NixOS configuration for the OpenWebUI service, enabling it by default on port 8080. The setup includes environment settings to disable telemetry and authentication, and it adds the openwebui.nix to the system modules.

systems/x86_64-linux/sgx/default.nix

@@ -10,6 +10,7 @@
     ./fileserver.nix
     ./backup.nix
     ./network.nix
+    ./openwebui.nix
   ];
 
   sops.secrets.pccs.sopsFile = ../../../.secrets/sgx/pccs.yaml;

systems/x86_64-linux/sgx/openwebui.nix

@@ -0,0 +1,16 @@
+{ ... }:
+{
+  services.open-webui = {
+    enable = true;
+    port = 8080;
+    host = "0.0.0.0";
+    enviroment = {
+      ANONYMIZED_TELEMETRY = "False";
+      DO_NOT_TRACK = "True";
+      SCARF_NO_ANALYTICS = "True";
+      OLLAMA_API_BASE_URL = "http://m4:11434";
+      # Disable authentication
+      WEBUI_AUTH = "False";
+    };
+  };
+}