chore: drop traffmonetizer version key, document its restart policy, add alloy .env.example

alloy/.env.example

@@ -0,0 +1,23 @@
+# Copy to .env and fill in. Never commit .env.
+#
+#   cp .env.example .env
+
+# Container hostname, and the Loki/Prometheus `instance` label. Set per host.
+ALLOY_HOSTNAME=alloy
+
+# Grafana Fleet Management endpoint, agent id (set per host) and user id.
+REMOTECFG_URL=
+REMOTECFG_ID=alloy
+REMOTECFG_USER=
+
+# Prometheus remote-write endpoint and user id.
+PROM_URL=
+PROM_USER=
+
+# Loki push endpoint and user id.
+LOKI_URL=
+LOKI_USER=
+
+# Cloud Access Policy token with metrics:write, logs:write and
+# fleet-management:read. Serves remotecfg, Prometheus and Loki.
+GRAFANA_TOKEN=