feat(portal): proxy Gitea SSH through HAProxy

- expose Gitea SSH through Portal on port 2223
- advertise the correct Gitea SSH user and domain
- add the Gitea host to Richie’s SSH config
- correct the local ACME challenge backend port

systems/jeeves/services/gitea.nix

@@ -26,10 +26,14 @@ in
       };
       service.DISABLE_REGISTRATION = true;
       server = {
-        DOMAIN = "tmmworkshop.com";
+        DOMAIN = "gitea.tmmworkshop.com";
         ROOT_URL = "https://gitea.tmmworkshop.com/";
         HTTP_PORT = 6443;
+        BUILTIN_SSH_SERVER_USER = "gitea";
+        SSH_USER = "gitea";
+        SSH_DOMAIN = "gitea.tmmworkshop.com";
         SSH_PORT = 2223;
+        SSH_LISTEN_HOST = "0.0.0.0";
         SSH_LISTEN_PORT = 2223;
         START_SSH_SERVER = true;
         PUBLIC_URL_DETECTION = "auto";