manager mcp: expose 'remind' tool sharing storage helper with agent surface

hive-c0re/src/manager_server.rs

@@ -307,6 +307,20 @@ async fn dispatch(req: &ManagerRequest, coord: &Arc<Coordinator>) -> ManagerResp
                 },
             }
         }
+        ManagerRequest::Remind {
+            message,
+            timing,
+            file_path,
+        } => match crate::agent_server::store_remind(
+            coord,
+            MANAGER_AGENT,
+            message,
+            timing,
+            file_path.as_deref(),
+        ) {
+            Ok(()) => ManagerResponse::Ok,
+            Err(message) => ManagerResponse::Err { message },
+        },
         ManagerRequest::RequestApplyCommit {
             agent,
             commit_ref,