feat(core): wire up the new ContextManager and AgentChatHistory (#25409)

packages/core/src/context/system-tests/lifecycle.golden.test.ts

@@ -5,6 +5,7 @@
  */
 
 import { describe, it, expect, vi, beforeAll, afterAll } from 'vitest';
+import fs from 'node:fs';
 import { SimulationHarness } from './simulationHarness.js';
 import { createMockLlmClient } from '../testing/contextTestUtils.js';
 import type { ContextProfile } from '../config/profiles.js';
@@ -28,6 +29,11 @@ expect.addSnapshotSerializer({
 });
 
 describe('System Lifecycle Golden Tests', () => {
+  afterAll(async () => {
+    fs.rmSync('/tmp/sim', { recursive: true, force: true });
+    fs.rmSync('mock', { recursive: true, force: true });
+  });
+
   beforeAll(() => {
     vi.spyOn(Math, 'random').mockReturnValue(0.5);
   });

packages/core/src/context/system-tests/simulationHarness.ts

@@ -59,7 +59,7 @@ export class SimulationHarness {
       sessionId: 'sim-session',
     });
     this.env = new ContextEnvironmentImpl(
-      mockLlmClient,
+      () => mockLlmClient,
       'sim-prompt',
       'sim-session',
       mockTempDir,