Detach subagents without archiving them (#1612)

* Add detach action for subagents

* Translate detached subagent connection error

* Address subagent detach review feedback

* Fix subagent integration test import

* Focus detached subagents as tabs

packages/client/src/daemon-client.test.ts

@@ -2762,6 +2762,48 @@ test("fetches agents via RPC with filters, sort, and pagination", async () => {
   });
 });
 
+test("detaches an agent through the namespaced detach RPC", async () => {
+  const logger = createMockLogger();
+  const mock = createMockTransport();
+
+  const client = new DaemonClient({
+    url: "ws://test",
+    clientId: "clsk_unit_test",
+    logger,
+    reconnect: { enabled: false },
+    transportFactory: () => mock.transport,
+  });
+  clients.push(client);
+
+  const connectPromise = client.connect();
+  mock.triggerOpen();
+  await connectPromise;
+
+  const promise = client.detachAgent("child-agent");
+
+  expect(mock.sent).toHaveLength(1);
+  const request = parseSentFrame(mock.sent[0]);
+  expect(request).toMatchObject({
+    type: "agent.detach.request",
+    agentId: "child-agent",
+  });
+  expect(typeof request.requestId).toBe("string");
+
+  mock.triggerMessage(
+    wrapSessionMessage({
+      type: "agent.detach.response",
+      payload: {
+        requestId: request.requestId,
+        agentId: "child-agent",
+        accepted: true,
+        error: null,
+      },
+    }),
+  );
+
+  await expect(promise).resolves.toBeUndefined();
+});
+
 test("sends active-scoped fetch_agents_request", async () => {
   const logger = createMockLogger();
   const mock = createMockTransport();