feat: add discovery

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

crates/churn/src/agent/discovery_client.rs

@@ -0,0 +1,21 @@
+use crate::api::Discovery;
+
+pub struct DiscoveryClient {
+    host: String,
+}
+
+impl DiscoveryClient {
+    pub fn new(discovery_host: impl Into<String>) -> Self {
+        Self {
+            host: discovery_host.into(),
+        }
+    }
+
+    pub async fn discover(&self) -> anyhow::Result<Discovery> {
+        tracing::info!(
+            "getting details from discovery endpoint: {}/discovery",
+            self.host.trim_end_matches('/')
+        );
+        crate::api::Discovery::get_from_host(&self.host).await
+    }
+}