Add Linode host configuration and WireGuard setup

- Introduced new configuration files for Linode host, including hardware configuration, toggles, and WireGuard settings.
- Updated flake.nix to include the new images.nix file for Linode image generation.
- Adjusted SSH key paths and secrets management for WireGuard to ensure proper integration with the new host setup.
- Enhanced firewall rules and NAT configuration for WireGuard to improve security and connectivity.

hosts/linode/toggles.nix

@@ -0,0 +1,25 @@
+_: {
+  timeZone = "America/Mexico_City";
+  locale = "en_US.UTF-8";
+  wireguard.enable = true;
+  network.enable = true;
+  secureHost = true;
+  ips = {
+    vps = "51.222.141.104";
+    wg-vps = "10.77.0.1";
+    wg-server = "10.77.0.2";
+    wg-friend1 = "10.8.0.2";
+    wg-friends = "10.8.0.0";
+  };
+  interfaces = {
+    linode = "eth0";
+  };
+  dev = {
+    nix.enable = true;
+    sh.enable = true;
+  };
+  shell = {
+    tools.enable = true;
+    config.enable = true;
+  };
+}