test(sessions): add enqueueSpeech to sessionEventBatching fake deps

The streamed-event batching test constructs SessionServiceDeps directly. Since the speak-tool narration work made enqueueSpeech a required dependency invoked when a response flushes, the fake deps must provide it or the test throws "this.d.enqueueSpeech is not a function".

Generated-By: PostHog Code
Task-Id: e012ce8b-197a-41c1-b96a-36bad4a1aa86

Author: jonmcwest

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

@@ -87,6 +87,7 @@ function createHarness() {
     log: noopLog,
     notifyPromptComplete,
     notifyPermissionRequest: vi.fn(),
+    enqueueSpeech: vi.fn(),
     taskViewedApi: { markActivity: vi.fn() },
     getPersistedConfigOptions: () => undefined,
     setPersistedConfigOptions: vi.fn(),