test(sessions): pin exactly one error session is stored

Round-2 review note: assertRunConfigPersisted read setSession.mock.calls.at(-1), which tolerates extra setSession calls. Assert the call count is exactly 1 so a future setup change that lets the auto-retry loop run can't slip an intermediate session past the last-call assertions.

Generated-By: PostHog Code
Task-Id: 88d22f31-54f1-4121-bd68-40c5958bb2cd

Author: robbie-c

packages/core/src/sessions/sessionServiceRetryConfig.test.ts

@@ -108,6 +108,10 @@ const CONNECT_PARAMS = {
 } as const;
 
 function assertRunConfigPersisted(setSession: ReturnType<typeof vi.fn>): void {
+  // Exactly one error session should be stored — pinning this stops a future
+  // setup change (e.g. one that lets the auto-retry loop run) from slipping an
+  // intermediate session past the last-call assertions below.
+  expect(setSession.mock.calls.length).toBe(1);
   const stored = setSession.mock.calls.at(-1)?.[0] as AgentSession;
   expect(stored.status).toBe("error");
   expect(stored.model).toBe("claude-fable-5");