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/flake.nix

@@ -0,0 +1,17 @@
+{
+  inputs,
+  nixpkgs,
+  ...
+}:
+nixpkgs.lib.nixosSystem {
+  modules = [
+    {_module.args = {inherit inputs;};}
+    inputs.home-manager.nixosModules.home-manager
+    inputs.stylix.nixosModules.stylix
+    inputs.sops-nix.nixosModules.sops
+    inputs.nixarr.nixosModules.default
+    inputs.nix-index-database.nixosModules.default
+    inputs.default-creds.nixosModules.default
+    ./configuration.nix
+  ];
+}