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.

nixos/systemd-boot.nix

@@ -0,0 +1,43 @@
+# Systemd-boot configuration for NixOS
+{pkgs, ...}: {
+  boot = {
+    bootspec.enable = true;
+    loader = {
+      efi.canTouchEfiVariables = true;
+      systemd-boot = {
+        enable = true;
+        consoleMode = "auto";
+        configurationLimit = 8;
+      };
+    };
+    tmp.cleanOnBoot = true;
+    kernelPackages = pkgs.linuxPackages_latest; # _zen, _hardened, _rt, _rt_latest, etc.
+
+    # Silent boot
+    kernelParams = [
+      "quiet"
+      "splash"
+      "rd.systemd.show_status=false"
+      "rd.udev.log_level=3"
+      "udev.log_priority=3"
+      "boot.shell_on_fail"
+    ];
+    consoleLogLevel = 0;
+    initrd.verbose = false;
+
+    # plymouth = {
+    #   enable = true;
+    #   theme = lib.mkForce "cuts_alt";
+    #   themePackages = with pkgs; [
+    #     (adi1090x-plymouth-themes.override {
+    #       selected_themes = ["cuts_alt"];
+    #     })
+    #   ];
+    # };
+  };
+
+  # To avoid systemd services hanging on shutdown
+  systemd.settings.Manager = {
+    DefaultTimeoutStopSec = "10s";
+  };
+}