ci(deploy): pause watchdog timer during container swap

The systemd watchdog (/etc/systemd/system/ocaml-lob-watchdog.timer)
races the deploy script's stop/rm/run sequence: the timer fires
every 30s, and if it ticks between [docker stop] and [docker rm]
it sees an unhealthy container and does [docker restart ocaml_lob],
which brings the container back up. The subsequent [docker rm]
then either fails (without -f) or leaves a stale container, and
[docker run --name ocaml_lob] hits a name conflict.

Saw this fire on the SSE deploy: build succeeded, deploy died
with "container name already in use" while watchdog logs showed
a restart firing in the same minute. Fix:

1. [systemctl stop ocaml-lob-watchdog.timer] before the swap,
   [systemctl start] via trap on EXIT so liveness coverage resumes
   even if the deploy fails mid-way.
2. [docker rm -f] for defense in depth — handles a running
   container regardless of how it got there.

Author: Builder106

.github/workflows/deploy.yml

@@ -138,9 +138,22 @@ jobs:
             echo "→ pulling $IMAGE"
             docker pull "$IMAGE"
 
+            # Pause the host watchdog (see /etc/systemd/system/ocaml-lob-watchdog.timer)
+            # for the duration of the swap. Otherwise it can fire between
+            # `docker stop` and `docker rm`, see the new container as down,
+            # and `docker restart` it back to running — at which point our
+            # subsequent `docker rm` either fails or leaves a stale container,
+            # and `docker run --name ocaml_lob` hits a name conflict. We
+            # restart the timer unconditionally after, even on failure, so
+            # liveness coverage resumes regardless of how the deploy exited.
+            trap 'sudo systemctl start ocaml-lob-watchdog.timer 2>/dev/null || true' EXIT
+            sudo systemctl stop ocaml-lob-watchdog.timer 2>/dev/null || true
+
             echo "→ replacing container"
+            # `-f` on rm forces removal of a running container — defense in
+            # depth in case anything (manual or otherwise) restarted it.
             docker stop ocaml_lob 2>/dev/null || true
-            docker rm   ocaml_lob 2>/dev/null || true
+            docker rm -f ocaml_lob 2>/dev/null || true
             docker run -d \
               --name ocaml_lob \
               --restart unless-stopped \