fix broadcast send for manager, deduplicate into coordinator.broadcast_send

hive-c0re/src/coordinator.rs

@@ -192,6 +192,27 @@ impl Coordinator {
         }
     }
 
+    /// Deliver `body` to every currently-registered agent, appending the
+    /// standard broadcast hint. Returns a list of per-agent error strings
+    /// for any that failed (empty = all ok). The sender's own inbox is
+    /// included — the hint text tells agents to ignore if no action needed.
+    pub fn broadcast_send(&self, from: &str, body: &str) -> Vec<String> {
+        const HINT: &str =
+            "\n\n⚠️ _hint: this was a broadcast and may not need any action from you_";
+        let broadcast_body = format!("{body}{HINT}");
+        let mut errors = Vec::new();
+        for agent_name in self.list_agents() {
+            if let Err(e) = self.broker.send(&hive_sh4re::Message {
+                from: from.to_owned(),
+                to: agent_name.clone(),
+                body: broadcast_body.clone(),
+            }) {
+                errors.push(format!("{agent_name}: {e}"));
+            }
+        }
+        errors
+    }
+
     pub fn agent_dir(name: &str) -> PathBuf {
         PathBuf::from(format!("{AGENT_RUNTIME_ROOT}/{name}"))
     }