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.

home/system/caelestia-shell/bar.nix

@@ -0,0 +1,68 @@
+{
+  programs.caelestia.settings.bar = {
+    clock.showIcon = false;
+    popouts.activeWindow = false;
+    persistent = true;
+    status = {
+      showBattery = true;
+      showMicrophone = false;
+      showLockStatus = false;
+      showBluetooth = true;
+      showAudio = true;
+      showKbLayout = false;
+      showNetwork = true;
+    };
+    workspaces = {
+      activeIndicator = true;
+      activeLabel = "󰪥 ";
+      activeTrail = false;
+      label = " ";
+      occupiedBg = true;
+      occupiedLabel = "󰪥 ";
+      showWindows = false;
+      shown = 5;
+    };
+    entries = [
+      {
+        id = "logo";
+        enabled = true;
+      }
+      {
+        id = "workspaces";
+        enabled = true;
+      }
+      {
+        id = "spacer";
+        enabled = true;
+      }
+      {
+        id = "activeWindow";
+        enabled = true;
+      }
+      {
+        id = "spacer";
+        enabled = true;
+      }
+      {
+        id = "tray";
+        enabled = true;
+      }
+      {
+        id = "clock";
+        enabled = true;
+      }
+      {
+        id = "statusIcons";
+        enabled = true;
+      }
+      {
+        id = "power";
+        enabled = true;
+      }
+    ];
+    tray = {
+      background = false;
+      recolour = false;
+    };
+  };
+}