use agentname in ws actions and frontend

frontend/src/backend.js

@@ -326,9 +326,9 @@ export async function getAgents() {
   return cache.agents;
 }
 
-export async function getAgent(agentId) {
+export async function getAgent(agentname) {
   const allAgents = await getAgents();
-  return allAgents.find(it => it.id == agentId);
+  return allAgents.find(it => it.agentname == agentname);
 }
 
 export function readStream(streamId) {