Cut the comment bloat from the Podman playbooks

Comment blocks now stay within three lines and explain only the non-obvious. Long histories, include examples, and commented-out code are gone. No task, key, or value changed; the only data change is comment text inside the generated unit files.

nextcloud/roles/postgres/handlers/main.yaml

@@ -1,13 +1,5 @@
 ---
-# Postgres is its own playbook (postgres/playbook.yml) and a rootless Quadlet
-# unit there. This handler runs as the connection user, which is what makes
-# `systemctl --user` work here.
-#
-# Required by postgres/roles/attach, which notifies it whenever this app's
-# drop-in changes: a new drop-in changes the generated unit, so Postgres must be
-# recreated to join the network — Quadlet has no live equivalent of
-# `podman network connect`. That is a few seconds of downtime for every attached
-# app, not just this one. See postgres/readme.md, "The trade-off".
+# A new drop-in changes the generated unit, so Postgres is recreated and every attached app restarts.
 - name: Restart Postgres
   ansible.builtin.systemd_service:
     name: "{{ postgres_unit }}"