fix(subscriptions): isolate observers and silence unrequested feeds

Filtered plugin observations shared a replaceable directory subscription with the app. Give each observation independent source ownership and route all application feeds through explicit demand, preserving combined listing and subscription.

plugin-examples/local-plugin/client/main.tsx

@@ -13,6 +13,7 @@ import { incrementRpc } from "../shared/increment";
 export function contributeClient(client: PluginClientContext) {
   const pills = new Map<string, PluginButtonRegistration>();
   let stopped = false;
+  const lifetime = new AbortController();
   const register = (agent: { id: string; workspaceId?: string | null }) => {
     if (stopped || !agent.workspaceId) return;
     pills.get(agent.id)?.remove();
@@ -39,20 +40,30 @@ export function contributeClient(client: PluginClientContext) {
     pills.get(agentId)?.remove();
     pills.delete(agentId);
   };
-  const unsubscribe = client.paseo.agents.subscribe((update) => {
-    if (update.kind === "remove") remove(update.agentId);
-    else register(update.agent);
-  });
   void client.paseo.agents
-    .list()
-    .then(({ entries }) => {
-      for (const { agent } of entries) register(agent);
+    .list({ subscribe: {}, signal: lifetime.signal })
+    .then(({ subscription }) => {
+      subscription.subscribe({
+        snapshot: ({ entries }) => {
+          for (const pill of pills.values()) pill.remove();
+          pills.clear();
+          for (const { agent } of entries) register(agent);
+        },
+        update: (message) => {
+          if (message.type !== "agent_update") return;
+          const update = message.payload;
+          if (update.kind === "remove") remove(update.agentId);
+          else register(update.agent);
+        },
+      });
       return undefined;
     })
-    .catch(() => undefined);
+    .catch((error) => {
+      if (!stopped) console.error("Agent observation failed", error);
+    });
   return () => {
     stopped = true;
-    unsubscribe();
+    lifetime.abort();
     for (const pill of pills.values()) pill.remove();
     pills.clear();
   };