update: system update & refactor

# Breaking Changes
- sops location movod to "system/dev/<dev-name>/sops/sops-conf.nix"
- flake devices declaration changes
- whole flake update

system/dev/dn-server/security/fail2ban.nix

@@ -0,0 +1,10 @@
+{
+  imports = [
+    (import ../../../modules/fail2ban.nix {
+      extraAllowList = [
+        "10.0.0.0/24"
+        "122.117.215.55"
+      ];
+    })
+  ];
+}