feat: add nix-secrets input and enable upstream proxy

hosts/alpha/default.nix

@@ -3,12 +3,14 @@
   username,
   config,
   email,
+  inputs,
   ...
 }: {
   imports = [
     ./hardware.nix
     ../common
     ../../modules/nixos/uptime-kuma.nix
+    ../../modules/nixos/upstream-proxy.nix
   ];
 
   sops.secrets = {
@@ -64,6 +66,11 @@
 
   users.users.nginx.extraGroups = ["acme"];
 
+  tux.services.nginxStreamProxy = {
+    enable = true;
+    upstreamServers = inputs.nix-secrets.proxy-servers;
+  };
+
   services = {
     nginx = {
       recommendedGzipSettings = true;