Harden production workflows and agent admission

deploy/showcase/agents/mixed.toml

@@ -1,4 +1,4 @@
-hostname = "agent-mixed"
+agent_id = "agent-01"
 state_dir = "/var/lib/monlet-agent"
 
 [labels]
@@ -8,7 +8,6 @@ role = "showcase"
 [server]
 enabled = true
 url = "http://server:8000"
-token = "monlet-dev-token"
 heartbeat_interval = "5s"
 batch_interval = "3s"
 
@@ -36,7 +35,7 @@ name = "Showcase critical (permanent webhook fail)"
 command = "/opt/monlet/checks/exit_2.sh"
 interval = "5s"
 timeout = "3s"
-dedupe_key = "agent-mixed:critical:fail"
+dedupe_key = "agent-01:critical:fail"
 
 [[checks]]
 id = "unknown_check"