fix: let systemd actually notice when the Zomboid container exits

`@bot restart` saves, sends RCON quit, and relies on the unit's Restart=always
to bring the server back. It never came back. The container sat at exited(0)
while the unit reported active/running with NRestarts=0, so the bot waited for
a startup that was never going to happen and the server stayed down until
someone noticed.

podman generate systemd emits Type=forking with ExecStart=podman start and a
PIDFile pointing at conmon. podman start returns immediately, so the process
systemd was told to supervise was never its child -- it warns about exactly
this in the journal, once per poll, and then does not notice the exit:

  zomboid.service: Supervising process 2431312 which is not our child.
  We'll most likely not notice when it exits.

That PIDFile is also stale by design: it embeds the container ID, so every
deploy that recreates the container leaves it pointing at nothing.

Type=simple with `podman start -a` keeps podman in the foreground as systemd's
own child, so the exit is seen and Restart=always does what it always claimed
to. stdout and stderr are discarded deliberately -- attaching re-emits the
container's output for systemd to capture straight back into the journal, which
is the flood the k8s-file driver exists to prevent. podman logs still has it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

ansible/roles/podman/tasks/containers/home/zomboid.yml

@@ -271,14 +271,41 @@
   vars:
     container_name: zomboid
 
-# Ensure zomboid restarts on any exit (including admin-triggered restarts)
+# Make systemd actually supervise the container, so it restarts on any exit --
-- name: configure zomboid systemd to always restart
+# including the clean one that `@bot restart` produces via RCON quit.
+#
+# `podman generate systemd` emits Type=forking with ExecStart=podman start and
+# a PIDFile pointing at conmon. podman start returns immediately, so the process
+# systemd is told to watch was never its child; it says so itself in the journal
+# ("Supervising process N which is not our child. We'll most likely not notice
+# when it exits") and it does not notice. The unit sat at active/running with
+# NRestarts=0 while the container was exited(0) and the server was down. The
+# PIDFile is worse than useless here: it embeds the container ID, so it goes
+# stale every time a deploy recreates the container.
+#
+# Type=simple with `podman start -a` keeps podman in the foreground as systemd's
+# own child, so the exit is seen and Restart=always fires.
+#
+# stdout/stderr are discarded on purpose. Attaching re-emits the container's
+# output on podman's stdout, which systemd would capture straight back into the
+# journal -- exactly the flood the k8s-file log driver exists to avoid. Nothing
+# is lost: `podman logs` still serves it from the container's own log.
+- name: configure zomboid systemd supervision
   become: true
   become_user: "{{ podman_user }}"
   ansible.builtin.lineinfile:
     path: "{{ podman_home }}/.config/systemd/user/zomboid.service"
-    regexp: "^Restart="
+    regexp: "{{ item.regexp }}"
-    line: "Restart=always"
+    line: "{{ item.line }}"
+    state: "{{ item.state | default('present') }}"
+    insertafter: '^\[Service\]'
+  loop:
+    - { regexp: '^Restart=', line: 'Restart=always' }
+    - { regexp: '^Type=', line: 'Type=simple' }
+    - { regexp: '^ExecStart=', line: 'ExecStart=/usr/bin/podman start -a zomboid' }
+    - { regexp: '^StandardOutput=', line: 'StandardOutput=null' }
+    - { regexp: '^StandardError=', line: 'StandardError=null' }
+    - { regexp: '^PIDFile=', line: '', state: absent }
   notify: reload zomboid systemd
 
 # Firewall logging for player IP correlation