refactor: split server modules into smaller more manageable files

modules/nixos-modules/server/jellyfin/proxy.nix

@@ -0,0 +1,25 @@
+{
+  lib,
+  config,
+  ...
+}: let
+  jellyfinPort = 8096;
+in {
+  config = lib.mkIf (config.services.jellyfin.enable && config.host.reverse_proxy.enable) {
+    host.reverse_proxy.subdomains.jellyfin = {
+      target = "http://localhost:${toString jellyfinPort}";
+
+      subdomain = config.services.jellyfin.subdomain;
+      extraSubdomains = config.services.jellyfin.extraSubdomains;
+
+      forwardHeaders.enable = true;
+
+      extraConfig = ''
+        client_max_body_size 20M;
+        add_header X-Content-Type-Options "nosniff";
+
+        proxy_buffering off;
+      '';
+    };
+  };
+}