Add the Yamtrack playbook

yamtrack/roles/valkey/handlers/main.yaml

@@ -0,0 +1,20 @@
+---
+# 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".
+- name: Restart Valkey
+  ansible.builtin.systemd_service:
+    name: "{{ valkey_unit }}"
+    scope: user
+    state: restarted
+    daemon_reload: true
+  listen: Restart Valkey