Keep MealQuest firewall rules first and off docker.service

Address review of the port 8090 firewall:

- Insert the three MealQuest rules at the top of DOCKER-USER, ahead of
  other projects' rules. Each run deletes every rule tagged
  "mealquest-firewall" and re-inserts them at positions 1-3, so re-runs
  restore the order and never duplicate.
- Scope the match to MealQuest's published address with
  --ctorigdst 10.60.1.14, so outbound container connections to a remote
  :8090 are not matched.
- Drop the docker.service ExecStartPost drop-in, which made a firewall
  error fatal to the shared Docker daemon. The unit is now PartOf= and
  WantedBy= docker.service: it re-runs on every Docker start or restart
  and fails visibly on its own without failing docker.service.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

deploy/systemd/mealquest-firewall.service

@@ -1,7 +1,17 @@
+# Applies the MealQuest DOCKER-USER rules (/usr/local/sbin/mealquest-firewall).
+#
+# PartOf= re-runs this unit whenever docker.service is stopped or restarted,
+# and WantedBy=docker.service starts it whenever docker.service starts. Both
+# are one-way: a failure here fails this unit visibly and never fails
+# docker.service.
+#
+# Start MealQuest only after this unit has succeeded:
+#   systemctl start mealquest-firewall && docker compose up -d
 [Unit]
 Description=Restrict MealQuest port 8090 to Traefik (DOCKER-USER)
 After=docker.service
 Requires=docker.service
+PartOf=docker.service
 
 [Service]
 Type=oneshot
@@ -9,4 +19,4 @@ RemainAfterExit=yes
 ExecStart=/usr/local/sbin/mealquest-firewall
 
 [Install]
-WantedBy=multi-user.target
+WantedBy=multi-user.target docker.service