fix: unify chat process and reply presentation

src/features/agent/hooks/use-agent-connection.test.tsx

@@ -0,0 +1,51 @@
+import { act, renderHook } from "@testing-library/react";
+import { afterEach, expect, it, vi } from "vitest";
+import { useAgentConnection } from "./use-agent-connection";
+
+afterEach(() => vi.useRealTimers());
+
+it("rechecks an offline service, probes on focus and clears work on unmount", async () => {
+  vi.useFakeTimers();
+  const getHealth = vi.fn().mockRejectedValueOnce(new Error("offline")).mockResolvedValue(undefined);
+  const client = { getHealth };
+  const { result, unmount } = renderHook(() => useAgentConnection(client, "project-a"));
+  await act(async () => {});
+  expect(result.current.connectionStatus).toBe("offline");
+  await act(async () => vi.advanceTimersByTimeAsync(1_000));
+  expect(result.current.connectionStatus).toBe("online");
+  expect(result.current.recoveryVersion).toBe(1);
+  await act(async () => window.dispatchEvent(new Event("focus")));
+  expect(getHealth).toHaveBeenCalledTimes(3);
+  unmount();
+  expect(vi.getTimerCount()).toBe(0);
+});
+
+it("discards a late result from a previous client and scope", async () => {
+  vi.useFakeTimers();
+  let finish!: () => void;
+  let oldSignal!: AbortSignal;
+  const oldClient = { getHealth: vi.fn((signal: AbortSignal) => { oldSignal = signal; return new Promise<void>((resolve) => { finish = resolve; }); }) };
+  const nextClient = { getHealth: vi.fn(async () => { throw new Error("next service offline"); }) };
+  const { result, rerender, unmount } = renderHook(({ client, scope }) => useAgentConnection(client, scope), { initialProps: { client: oldClient, scope: "old" } });
+  await act(async () => {});
+  rerender({ client: nextClient, scope: "next" });
+  await act(async () => {});
+  expect(oldSignal.aborted).toBe(true);
+  await act(async () => finish());
+  expect(result.current.connectionStatus).toBe("offline");
+  unmount();
+});
+
+it("aborts a stalled probe and recovers on the next retry", async () => {
+  vi.useFakeTimers();
+  const getHealth = vi.fn().mockImplementationOnce((signal: AbortSignal) => new Promise<void>((_resolve, reject) => {
+    signal.addEventListener("abort", () => reject(new DOMException("timeout", "AbortError")), { once: true });
+  })).mockResolvedValue(undefined);
+  const client = { getHealth };
+  const { result, unmount } = renderHook(() => useAgentConnection(client, "project"));
+  await act(async () => vi.advanceTimersByTimeAsync(5_000));
+  expect(result.current.connectionStatus).toBe("offline");
+  await act(async () => vi.advanceTimersByTimeAsync(1_000));
+  expect(result.current.connectionStatus).toBe("online");
+  unmount();
+});