feat(#1014): rename manager agent root→ruth across all crates + frontend

frontend/packages/dashboard/src/flow.js

@@ -264,10 +264,8 @@ import {
     function knownAgents() {
       // Read live from the flow-local containers cache so newly-spawned
       // agents become addressable without a manual reload.
-      // Broker uses the literal recipient `manager` for the manager's
-      // inbox, not the container name `hm1nd`.
       const names = Array.from(flowContainers.values())
-        .map((c) => (c.is_manager ? 'manager' : c.name));
+        .map((c) => c.name);
       // `*` fans out to every registered agent (server-side
       // broadcast_send).
       names.unshift('*');