refactor: moved nixos modules to dendrite pattern

modules/nixos/programs/paperless/fail2ban.nix

@@ -0,0 +1,36 @@
+{...}: {
+  flake.nixosModules.paperless-fail2ban = {
+    config,
+    lib,
+    pkgs,
+    ...
+  }: {
+    config = lib.mkIf (config.services.paperless.enable && config.services.fail2ban.enable) {
+      environment.etc = {
+        "fail2ban/filter.d/paperless.local".text = (
+          pkgs.lib.mkDefault (pkgs.lib.mkAfter ''
+            [Definition]
+            failregex = Login failed for user `.*` from (?:IP|private IP) `<HOST>`\.$
+            ignoreregex =
+
+          '')
+        );
+      };
+
+      services.fail2ban = {
+        jails = {
+          paperless.settings = {
+            enabled = true;
+            filter = "paperless";
+            action = ''iptables-multiport[name=HTTP, port="http,https"]'';
+            logpath = "${config.services.paperless.dataDir}/log/*.log";
+            backend = "auto";
+            findtime = 600;
+            bantime = 600;
+            maxretry = 5;
+          };
+        };
+      };
+    };
+  };
+}