feat: add common queue

Signed-off-by: kjuulh <contact@kjuulh.io>

crates/churn/src/agent/models.rs

@@ -0,0 +1,20 @@
+use std::{collections::BTreeMap, fmt::Display};
+
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize, Clone, Debug)]
+#[serde(tag = "type")]
+pub enum Commands {
+    ScheduleTask {
+        task: String,
+        properties: BTreeMap<String, String>,
+    },
+}
+
+impl Display for Commands {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(match self {
+            Commands::ScheduleTask { .. } => "schedule_task",
+        })
+    }
+}