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.

yamtrack/roles/valkey/handlers/main.yaml

@@ -1,16 +1,6 @@
 ---
-# Valkey is its own playbook (valkey/playbook.yml) and a rootless Quadlet unit
-# there. This handler runs as the connection user, so `systemctl --user` works
-# without setting XDG_RUNTIME_DIR.
-#
-# Required by valkey/roles/attach, which notifies it whenever this app's drop-in
-# changes: a new drop-in changes the generated unit, so Valkey must be recreated
-# to join the network — Quadlet has no live equivalent of
-# `podman network connect`.
-#
-# The cost is a cold cache for every attached app, not lost data — but note that
-# attached means every cache client, not just Yamtrack. See valkey/readme.md,
-# "The trade-off".
+# A new drop-in changes the generated unit, so Valkey must be recreated to join the network.
+# That restarts every attached client, not just Yamtrack.
 - name: Restart Valkey
   ansible.builtin.systemd_service:
     name: "{{ valkey_unit }}"

yamtrack/roles/valkey/tasks/main.yaml

@@ -1,31 +1,10 @@
 ---
-# Attach this app's network to the shared Valkey unit.
-#
-# Valkey knows nothing about its clients, exactly like Caddy and Postgres: a
-# service joins by dropping 50-yamtrack.conf and the shared
-# 10-network-aliases.conf next to valkey.container. The canonical way to do that
-# is the shared include below — it writes the same bytes every service writes,
-# asserts that yamtrack.network already exists, and notifies the "Restart Valkey"
-# handler defined in this role.
-#
-# `valkey` is the host REDIS_URL asks for — the container name, not the shared
-# `redis` alias, which is there for the clients whose config.php says `redis`.
-# The Docker-era container was given `redis://valkey:6379` too, so the URL is
-# unchanged.
-#
-# This runs in the roles phase, which is after the register include in
-# playbook.yml's pre_tasks has created yamtrack.network.
 
+# Runs in the roles phase, after the register include in pre_tasks created the network.
 - name: Attach Yamtrack to Valkey
   ansible.builtin.include_tasks: "{{ playbook_dir }}/../valkey/roles/attach/tasks/main.yaml"
 
-# On a first attach the drop-in is new, so Valkey has to be recreated to join
-# yamtrack_net — and that restart is a *handler*, which by default runs at the
-# end of the play, after the yamtrack role has already started the app. The app
-# would then come up before `valkey` resolves, fail its own checks, and fail the
-# play on a machine where nothing is actually wrong.
-#
-# Flushing applies the new drop-in before the app starts. On later runs the
-# drop-in is unchanged, nothing is pending, and this is a no-op.
+# The restart is a handler, so it would run after the yamtrack role starts the app.
+# Flushing applies the new drop-in before the app starts; later runs are a no-op.
 - name: Apply the Valkey network change before starting Yamtrack
   ansible.builtin.meta: flush_handlers