feat(tazjin/polyanka): deploy a tgsa instance

Change-Id: I8a32c093eb0ac8f6a0c3cfbb358d46d97d0c3b17
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5469
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>

users/tazjin/nixos/modules/default.nix

@@ -0,0 +1,2 @@
+# Make readTree happy at this level.
+_: { }

users/tazjin/nixos/modules/tgsa.nix

@@ -0,0 +1,24 @@
+{ config, depot, lib, pkgs, ... }:
+
+{
+  systemd.services.tgsa = {
+    description = "telegram -> SA bbcode thing";
+    wantedBy = [ "multi-user.target" ];
+
+    serviceConfig = {
+      DynamicUser = true;
+      Restart = "always";
+      ExecStart = "${depot.users.tazjin.tgsa}/bin/tgsa";
+    };
+  };
+
+  services.nginx.virtualHosts."tgsa" = {
+    serverName = "tgsa.tazj.in";
+    enableACME = true;
+    forceSSL = true;
+
+    locations."/" = {
+      proxyPass = "http://localhost:8472";
+    };
+  };
+}