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.

postgres/roles/attach/tasks/main.yaml

@@ -1,45 +1,12 @@
 ---
-# Attach a service's network to Postgres.
-#
-# Postgres is the *base* unit and knows nothing about its clients, the same way
-# Caddy knows nothing about its upstreams. A service that needs a database adds
-# itself by dropping files next to postgres.container, and Quadlet merges them in.
-#
-# Include this from a service playbook:
-#
-#   - name: Attach this service to Postgres
-#     ansible.builtin.include_tasks: "{{ playbook_dir }}/../postgres/roles/attach/tasks/main.yaml"
-#     vars:
-#       network_name: "{{ network_name }}"
-#
-# The including play must:
-#
-#   1. have created {{ network_name }}.network already — caddy/roles/register
-#      does that, and every service here that needs a database is also behind
-#      Caddy, so its register include comes first;
-#   2. run the `podman` role (or include its task file and define the same four
-#      vars), for podman_user and quadlet_dir;
-#   3. define a "Restart Postgres" handler — see
-#      roles/postgres/handlers/main.yaml for the exact snippet; and
-#   4. flush handlers before starting the app, on a first attach. This include
-#      notifies that restart, so by default it runs at the end of the play —
-#      after the app has already started and failed to resolve `db`. A
-#      `meta: flush_handlers` immediately after this include is enough; see
-#      tandoor/roles/postgres for the working example.
-#
-# It runs as the connection user, which must be the rootless podman_user.
-#
-# A service may instead write these two files from its own role; the bytes have
-# to match this file exactly, or the two will overwrite each other on every run.
 
 - name: "Check that the {{ network_name }} network unit exists"
   ansible.builtin.stat:
     path: "{{ quadlet_dir }}/{{ network_name }}.network"
   register: postgres_attach_network
 
-# A drop-in naming a .network file that does not exist makes Quadlet fail to
-# generate the whole postgres unit, with a message that does not mention the
-# drop-in at all. Fail here instead, where the cause is obvious.
+# A drop-in naming a missing network breaks unit generation with an unrelated
+# error, so fail here instead.
 - name: "Fail if {{ network_name }} has no network unit"
   ansible.builtin.assert:
     that: postgres_attach_network.stat.exists
@@ -64,20 +31,14 @@
     group: "{{ podman_user }}"
     mode: '0644'
     content: |
-      # Added by the {{ network_name }} playbook. Do not edit by hand.
-      #
-      # Deleting this file removes the network from {{ postgres_container | default('postgres') }} on
-      # the next daemon-reload; nothing else changes.
+      # Added by {{ network_name }}. Deleting it detaches the network from
+      # {{ postgres_container | default('postgres') }} on the next daemon-reload.
       [Container]
       Network={{ network_name }}.network
   notify: Restart Postgres
 
-# NetworkAlias= applies to every network the container joins, which is exactly
-# right for a hub: every app in this repo reaches postgres as `db` (nextcloud,
-# gitea, tandoor and outline use the alias; the rest use the container name).
-# It is a fixed value in one shared file, not a per-service option, so the same
-# bytes are written no matter how many services attach — two services writing
-# their own aliases would make Quadlet pass --network-alias twice.
+# NetworkAlias applies to every network, so one shared file holds the fixed
+# alias. Two services writing their own would pass --network-alias twice.
 - name: "Give {{ postgres_container | default('postgres') }} the shared 'db' alias"
   ansible.builtin.copy:
     dest: >-