feat(host): atproto-likes web UI at atproto.commoninternet.net

Imports the notplants-atproto module: Docker daemon (this host had none), a
systemd unit running the project's docker-compose stack, and an nginx vhost
proxying to it on 127.0.0.1:8731 with ACME and websocket support.

Opens 80/443 publicly. Until now only 22 was open and everything else was
tailnet-only, so this is a real change in exposure — nginx is now reachable
from the internet. The existing oc.commoninternet.net vhost is untouched and
stays bound to the tailscale IP.

nix/atproto-likes.nix is a COPY; the canonical file lives in the project repo
at /srv/project-orchestrator/projects/notplants-atproto/nix/. Pure evaluation
forbids importing an absolute path outside the flake tree, so it has to be
duplicated here — and a new file must be git-added or nix silently ignores it.

ACME currently FAILS: *.commoninternet.net is a wildcard pointing at
143.244.213.108, so the HTTP-01 challenge is answered by that host (500).
nginx serves a self-signed placeholder and starts fine. Fix is an explicit
A record atproto.commoninternet.net -> 168.119.126.100, then
`systemctl start acme-atproto.commoninternet.net.service`.

Applied with nixos-rebuild switch; container healthy, TLS proxy and wss
verified end to end.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SmEK2voMnBa23495aLk1Ce

nix/atproto-likes.nix

@@ -0,0 +1,89 @@
+# atproto-likes — the "most-liked accounts" web UI, run as a docker-compose stack
+# behind the host's nginx.
+#
+# ⚠️  COPY. Canonical source:
+#     /srv/project-orchestrator/projects/notplants-atproto/nix/atproto-likes.nix
+#     A flake cannot import an absolute path outside its own tree under pure
+#     evaluation, so the module is copied here. Re-copy after editing the original.
+#
+# Import this from the host configuration:
+#   imports = [ /srv/project-orchestrator/projects/notplants-atproto/nix/atproto-likes.nix ];
+#
+# What it sets up:
+#   * the Docker daemon (this host had none before)
+#   * a systemd unit that builds and runs docker-compose.yml from the project checkout
+#   * an nginx vhost for atproto.commoninternet.net with a Let's Encrypt cert,
+#     proxying to the container on 127.0.0.1:8731
+#   * ports 80/443 open (they were closed — only 22 was public)
+#
+# DNS: *.commoninternet.net is a wildcard pointing at 143.244.213.108, which is NOT
+# this host. Until an explicit A record
+#     atproto.commoninternet.net -> 168.119.126.100
+# overrides that wildcard, ACME's HTTP-01 challenge cannot succeed and the domain
+# keeps resolving elsewhere. nginx still starts in the meantime — NixOS installs a
+# self-signed placeholder cert — so nothing else on the host is affected.
+{ config, pkgs, lib, ... }:
+
+let
+  projectDir = "/srv/project-orchestrator/projects/notplants-atproto";
+  domain = "atproto.commoninternet.net";
+  hostPort = 8731;                        # must match the ports: mapping in docker-compose.yml
+  compose = "${pkgs.docker-compose}/bin/docker-compose";
+in
+{
+  virtualisation.docker = {
+    enable = true;
+    # Reclaim dangling images from repeated `--build` runs.
+    autoPrune = { enable = true; dates = "weekly"; };
+  };
+
+  # Build + run the compose stack. Type=oneshot with RemainAfterExit: compose
+  # detaches, and the containers' own restart policy keeps them alive.
+  systemd.services.atproto-likes = {
+    description = "atproto-likes — most-liked-accounts web UI (docker compose)";
+    wantedBy = [ "multi-user.target" ];
+    after = [ "docker.service" "docker.socket" "network-online.target" ];
+    requires = [ "docker.service" ];
+    wants = [ "network-online.target" ];
+    path = [ pkgs.docker pkgs.docker-compose ];
+    serviceConfig = {
+      Type = "oneshot";
+      RemainAfterExit = true;
+      WorkingDirectory = projectDir;
+      # A cold `--build` pulls python:3.12-slim and installs pip deps.
+      TimeoutStartSec = "1800";
+      ExecStart = "${compose} up -d --build --remove-orphans";
+      ExecStop = "${compose} down";
+      Restart = "on-failure";
+      RestartSec = "30s";
+    };
+  };
+
+  services.nginx = {
+    enable = true;
+    recommendedProxySettings = true;
+    virtualHosts.${domain} = {
+      forceSSL = true;
+      enableACME = true;
+      locations."/" = {
+        proxyPass = "http://127.0.0.1:${toString hostPort}";
+        # The loading page streams scan progress over a websocket.
+        proxyWebsockets = true;
+        # A cold scan can run for minutes with the socket open; the default 60s
+        # proxy read timeout would cut the loading page off mid-flower.
+        extraConfig = ''
+          proxy_read_timeout 1800s;
+          proxy_send_timeout 1800s;
+        '';
+      };
+    };
+  };
+
+  security.acme = {
+    acceptTerms = true;
+    defaults.email = "mfowler.email@protonmail.com";
+  };
+
+  # Public HTTP/HTTPS. Before this, only 22 was open on the public interface.
+  networking.firewall.allowedTCPPorts = [ 80 443 ];
+}

nix/hosts/cc-ci-orchestrator-hetzner/configuration.nix

@@ -9,6 +9,13 @@
 {
   # hardware.nix is the nixos-infect generated hardware-configuration.nix (see README Stage 2a).
 
+  # atproto-likes — the notplants-atproto "most-liked accounts" web UI, served at
+  # atproto.commoninternet.net. Brings in Docker + a compose stack + an nginx vhost
+  # with ACME, and opens 80/443 (previously only 22 was public). Canonical source of
+  # the module is the project repo; ../atproto-likes.nix is a copy kept in this tree
+  # because pure evaluation cannot import a path outside the flake.
+  imports = [ ../../atproto-likes.nix ];
+
   services.openssh = {
     enable = true;
     settings.PermitRootLogin = "yes";