set an agent's initial agents.md at create

hive-agent/src/main.rs

@@ -505,6 +505,8 @@ async fn serve_main<S: Surface>(socket: &Path, poll_ms: u64) -> Result<()> {
     swarm_agent_state::spawn(&bus, login_state.clone());
     // Once per start: a new icon only arrives with a new harness process.
     swarm_agent_icon::spawn();
+    // Before the mirror and before any turn reads the file.
+    swarm_agents_md::seed_initial().await;
     // At start and on every change, so the swarm can read it while the
     // agent is stopped.
     swarm_agents_md::spawn();