Add new server modules and configurations for various services

- Introduced `default-creds` module for managing default credentials with Umami integration.
- Added `fail2ban` module for brute-force attack protection with configurable ban times.
- Created `firewall` module to enable and configure basic firewall settings.
- Implemented `gitea` module for self-hosted Git service with PostgreSQL backend.
- Developed `glance` module for a customizable dashboard with various widgets and themes.
- Added `iknowyou` module for a self-hosted password manager with production and demo environments.
- Introduced `kernel-hardening` module for enhancing kernel security settings.
- Created `mazanoke` module for a simple web application with Nginx integration.
- Added `mealie` module for a self-hosted meal planning application.
- Implemented `stirling-pdf` module for PDF generation service.
- Developed `umami` module for self-hosted analytics with secret management.
- Added `ssh` module for secure SSH configuration with user restrictions.
- Introduced `nixy` theme for a customized aesthetic experience across services.

hosts/server/secrets/default.nix

@@ -0,0 +1,33 @@
+{pkgs, ...}: {
+  sops = {
+    age.keyFile = "/home/hadi/.config/sops/age/keys.txt";
+    defaultSopsFile = ./secrets.yaml;
+    secrets = {
+      sshconfig = {
+        owner = "hadi";
+        path = "/home/hadi/.ssh/config";
+        mode = "0600";
+      };
+      github-key = {
+        owner = "hadi";
+        path = "/home/hadi/.ssh/github";
+        mode = "0600";
+      };
+      signing-key = {
+        owner = "hadi";
+        path = "/home/hadi/.ssh/key";
+        mode = "0600";
+      };
+      signing-pub-key = {
+        owner = "hadi";
+        path = "/home/hadi/.ssh/key.pub";
+        mode = "0600";
+      };
+    };
+  };
+
+  environment.systemPackages = with pkgs; [
+    sops
+    age
+  ];
+}