refactor: split server modules into smaller more manageable files

modules/nixos-modules/server/forgejo/fail2ban.nix

@@ -0,0 +1,32 @@
+{
+  lib,
+  config,
+  pkgs,
+  ...
+}: {
+  config = lib.mkIf (config.services.forgejo.enable && config.services.fail2ban.enable) {
+    environment.etc = {
+      "fail2ban/filter.d/forgejo.local".text = lib.mkIf config.services.forgejo.enable (
+        pkgs.lib.mkDefault (pkgs.lib.mkAfter ''
+          [Definition]
+          failregex = ".*(Failed authentication attempt|invalid credentials|Attempted access of unknown user).* from <HOST>"
+        '')
+      );
+    };
+
+    services.fail2ban = {
+      jails = {
+        forgejo-iptables.settings = lib.mkIf config.services.forgejo.enable {
+          enabled = true;
+          filter = "forgejo";
+          action = ''iptables-multiport[name=HTTP, port="http,https"]'';
+          logpath = "${config.services.forgejo.settings.log.ROOT_PATH}/*.log";
+          backend = "auto";
+          findtime = 600;
+          bantime = 600;
+          maxretry = 5;
+        };
+      };
+    };
+  };
+}