Converted all external tool calling to async

server/src/rebuild.rs

@@ -95,6 +95,7 @@ pub async fn rebuild_and_restart(
     // 1. Gracefully stop all running agents.
     let running_count = agents
         .list_agents()
+        .await
         .unwrap_or_default()
         .iter()
         .filter(|a| a.status == crate::agents::AgentStatus::Running)
@@ -102,7 +103,7 @@ pub async fn rebuild_and_restart(
     if running_count > 0 {
         slog!("[rebuild] Stopping {running_count} running agent(s) before rebuild");
     }
-    agents.kill_all_children();
+    agents.kill_all_children().await;
 
     // 2. Find the workspace root (parent of the server binary's source).
     //    CARGO_MANIFEST_DIR at compile time points to the `server/` crate;