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.

caddy/vars/default.yml

@@ -1,46 +1,26 @@
 ---
-# ---------------------------------------------------------------------------
-# Rootless Podman / Quadlet
-# ---------------------------------------------------------------------------
-# The container user is derived from the connection: this play carries no
-# become, so the modules run as — and the Quadlet units belong to — whoever
-# Ansible connects as. Requires gather_facts (set explicitly in playbook.yml).
-#
-# To use a different user you would have to reintroduce become_user, which is
-# exactly what this design avoids; the podman role fails loudly if the resolved
-# user is root.
+# Set gather_facts: true, because these values come from ansible_facts.
 podman_user: "{{ ansible_facts['user_id'] }}"
 
-# State and config live in the user's home, not /var/lib. Taken from the
-# user_dir fact, so this is correct even for users whose home is not
-# /home/<name>.
 podman_data_dir: "{{ ansible_facts['user_dir'] }}/podman-data"
 quadlet_dir: "{{ ansible_facts['user_dir'] }}/.config/containers/systemd"
 
-# Rootless containers cannot publish ports below 1024 without this sysctl.
-# Caddy needs 80/443, so patching it down to 80 is the standard trade.
+# Caddy publishes 80/443, which needs the unprivileged port floor lowered.
 podman_unprivileged_port_start: 80
 
-# ---------------------------------------------------------------------------
-# Caddy
-# ---------------------------------------------------------------------------
 caddy_name: caddy
 caddy_unit: "{{ caddy_name }}.service"
 
-# Fully qualified on purpose: rootless Podman resolves short names against
-# unqualified-search-registries, and there is no TTY to answer a prompt when
-# the systemd unit starts.
+# Fully qualified, because short names prompt for a registry and the unit has
+# no TTY.
 caddy_image: docker.io/library/caddy:latest
 
 host_directory: "{{ podman_data_dir }}/caddy"
 caddyfile_path: "{{ host_directory }}/conf/Caddyfile"
 
-# Quadlet drop-in directory for the Caddy unit. Services register themselves
-# here; see the "How services register themselves" section of readme.md.
-# Caddy itself never lists its upstream networks.
 caddy_dropin_dir: "{{ quadlet_dir }}/{{ caddy_name }}.container.d"
 
-# Host ports. 443/udp is HTTP/3 (QUIC).
+# 443/udp carries HTTP/3.
 caddy_ports:
   - "80:80"
   - "443:443"