Implement r5500 media stack configuration with NFS and Docker services

- Added configuration for media stack on r5500, including paths for Jellyfin, Sonarr, Radarr, and other media services.
- Integrated NFS client for accessing Jellyfin libraries from nixdesk.
- Established Docker services for Dispatcharr and Organizr, including necessary user and group setups.
- Created systemd services for managing media directories and ensuring proper permissions.

modules/hosts/r5500/_services/radarr.nix

@@ -0,0 +1,20 @@
+{ lib, mediaStackPaths, ... }:
+{
+  services.radarr = {
+    enable = true;
+    dataDir = mediaStackPaths.radarrDataDir;
+  };
+
+  users.groups.radarr = { };
+  users.users.radarr = {
+    isSystemUser = true;
+    group = "radarr";
+    extraGroups = [ "media" ];
+  };
+
+  systemd.services.radarr.serviceConfig.ReadWritePaths = lib.mkAfter [
+    mediaStackPaths.radarrDataDir
+  ];
+
+  networking.firewall.allowedTCPPorts = [ 7878 ];
+}