agent loop: claude drives; tool envelope (log/run/status/log)

hive-c0re/src/agent_server.rs

@@ -101,5 +101,11 @@ fn dispatch(req: &AgentRequest, agent: &str, broker: &Broker) -> AgentResponse {
                 message: format!("{e:#}"),
             },
         },
+        AgentRequest::Status => match broker.count_pending(agent) {
+            Ok(unread) => AgentResponse::Status { unread },
+            Err(e) => AgentResponse::Err {
+                message: format!("{e:#}"),
+            },
+        },
     }
 }

hive-c0re/src/broker.rs

@@ -86,6 +86,20 @@ impl Broker {
         Ok(())
     }
 
+    /// Number of undelivered messages addressed to `recipient`. Non-mutating
+    /// — used by the harness to surface "N unread" in tool-result status
+    /// lines without popping the queue.
+    pub fn count_pending(&self, recipient: &str) -> Result<u64> {
+        let conn = self.conn.lock().unwrap();
+        let n: i64 = conn.query_row(
+            "SELECT COUNT(*) FROM messages
+              WHERE recipient = ?1 AND delivered_at IS NULL",
+            params![recipient],
+            |row| row.get(0),
+        )?;
+        Ok(u64::try_from(n.max(0)).unwrap_or(0))
+    }
+
     pub fn recv(&self, recipient: &str) -> Result<Option<Message>> {
         let conn = self.conn.lock().unwrap();
         let row: Option<(i64, String, String, String)> = conn