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.

valkey/vars/default.yml

@@ -1,58 +1,29 @@
 ---
-# ---------------------------------------------------------------------------
-# Rootless Podman / Quadlet
-# ---------------------------------------------------------------------------
-# Duplicated on purpose from caddy/vars/default.yml: a play cannot include that
-# file wholesale, because it also sets `host_directory` — to the Caddy data
-# directory — and every playbook defines that for itself. Keep these three in
-# sync with caddy/vars/default.yml. (Its fourth, podman_unprivileged_port_start,
-# belongs to the podman tasks, which this play does not run: Valkey publishes
-# nothing host-side.)
-#
-# podman_user is derived from the connection: this play carries no become, so
-# the Quadlet units belong to whoever Ansible connects as. Requires gather_facts
-# (set in playbook.yml).
+# A play cannot include caddy/vars/default.yml, which also sets host_directory,
+# so keep these in sync with it. Set gather_facts: true for the facts below.
 podman_user: "{{ ansible_facts['user_id'] }}"
 podman_data_dir: "{{ ansible_facts['user_dir'] }}/podman-data"
 quadlet_dir: "{{ ansible_facts['user_dir'] }}/.config/containers/systemd"
 
-# ---------------------------------------------------------------------------
-# Valkey
-# ---------------------------------------------------------------------------
 container_name: valkey
 unit_name: "{{ container_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. The Docker-era playbook said `valkey/valkey:alpine`.
+# Fully qualified, because short names prompt for a registry and the unit has
+# no TTY.
 image: docker.io/valkey/valkey:alpine
 
 host_directory: "{{ podman_data_dir }}/{{ container_name }}"
 
-# The image's WORKDIR and VOLUME: the RDB snapshot and, if it is ever enabled,
-# the AOF live here. The contents are disposable — nothing needs to be copied
-# off monoco — but the mount is not: RDB persistence is on by default, and the
-# graceful stop of a rebuild writes a final snapshot here that the next
-# container loads. Keep it unless you also set `save ""`. See readme.md, "The
-# trade-off".
+# The image volume holds the RDB snapshot. A graceful stop writes a final one
+# here, so keep the mount unless you also set `save ""`.
 data_mount: /data
 
-# The uid and gid of the image's `valkey` account. The uid is 999 — the one the
-# anonymous Docker volume was owned by (docs/podman-compat-audit.md §3.2) — but
-# the gid is *1000*, not 999: Alpine already has a gid 999, and the image's
-# Dockerfile says so outright ("alpine already has a gid 999, so we'll use the
-# next id") before dropping to the account with `setpriv --regid=valkey`.
-# Mapping both ids onto podman_user is what keeps {{ host_directory }} — owner
-# and group alike — with the connection user, instead of stranding the group on
-# a subgid the moment valkey-server writes a snapshot.
+# The image account is uid 999 and gid 1000, not 999: Alpine already has a gid
+# 999. Mapping both keeps host_directory owned by podman_user.
 app_uid: 999
 app_gid: 1000
 
-# No PublishPort, on purpose: the Docker-era playbook published 127.0.0.1:6379,
-# and nothing on the host needs it. Clients reach Valkey over the app networks
-# that attach themselves; {{ container_port }} is the port inside the container.
+# No PublishPort: clients reach Valkey over the app networks, not the host.
 container_port: 6379
 
-# Quadlet drop-in directory for the Valkey unit. Services attach themselves
-# here; see the "How services attach themselves" section of readme.md.
 valkey_dropin_dir: "{{ quadlet_dir }}/{{ container_name }}.container.d"