fix(core): resolve scheduler hang and verify with unit tests

This commit:
1. Rips out the redundant MessageBus listener in Scheduler.ts that caused race conditions.
2. Adds a unit test to verify the Scheduler no longer subscribes to TOOL_CONFIRMATION_REQUEST.
3. Adds emitFeedback to MessageBus.ts for policy rejections.
4. Adds a unit test to verify that user feedback is emitted on policy denial.

packages/core/src/confirmation-bus/message-bus.test.ts

@@ -8,6 +8,7 @@ import { describe, it, expect, beforeEach, vi } from 'vitest';
 import { MessageBus } from './message-bus.js';
 import { PolicyEngine } from '../policy/policy-engine.js';
 import { PolicyDecision } from '../policy/types.js';
+import { coreEvents } from '../utils/events.js';
 import {
   MessageBusType,
   type ToolConfirmationRequest,
@@ -23,6 +24,7 @@ describe('MessageBus', () => {
   beforeEach(() => {
     policyEngine = new PolicyEngine();
     messageBus = new MessageBus(policyEngine);
+    vi.restoreAllMocks();
   });
 
   describe('publish', () => {
@@ -80,11 +82,14 @@ describe('MessageBus', () => {
       expect(responseHandler).toHaveBeenCalledWith(expectedResponse);
     });
 
-    it('should emit rejection and response when policy denies', async () => {
+    it('should emit rejection, response, and user feedback when policy denies', async () => {
       vi.spyOn(policyEngine, 'check').mockResolvedValue({
         decision: PolicyDecision.DENY,
       });
 
+      const feedbackSpy = vi
+        .spyOn(coreEvents, 'emitFeedback')
+        .mockImplementation(() => {});
       const responseHandler = vi.fn();
       const rejectionHandler = vi.fn();
       messageBus.subscribe(
@@ -104,6 +109,11 @@ describe('MessageBus', () => {
 
       await messageBus.publish(request);
 
+      expect(feedbackSpy).toHaveBeenCalledWith(
+        'error',
+        expect.stringContaining('test-tool'),
+      );
+
       const expectedRejection: ToolPolicyRejection = {
         type: MessageBusType.TOOL_POLICY_REJECTION,
         toolCall: { name: 'test-tool', args: {} },

packages/core/src/scheduler/scheduler.test.ts

@@ -66,6 +66,7 @@ vi.mock('./tool-modifier.js');
 
 import { Scheduler } from './scheduler.js';
 import type { Config } from '../config/config.js';
+import { MessageBusType } from '../confirmation-bus/types.js';
 import type { MessageBus } from '../confirmation-bus/message-bus.js';
 import type { PolicyEngine } from '../policy/policy-engine.js';
 import type { ToolRegistry } from '../tools/tool-registry.js';
@@ -327,6 +328,15 @@ describe('Scheduler (Orchestrator)', () => {
     vi.clearAllMocks();
   });
 
+  describe('Initialization', () => {
+    it('should NOT subscribe to TOOL_CONFIRMATION_REQUEST on message bus', () => {
+      expect(mockMessageBus.subscribe).not.toHaveBeenCalledWith(
+        MessageBusType.TOOL_CONFIRMATION_REQUEST,
+        expect.any(Function),
+      );
+    });
+  });
+
   describe('Phase 1: Ingestion & Resolution', () => {
     it('should create an ErroredToolCall if tool is not found', async () => {
       vi.mocked(mockToolRegistry.getTool).mockReturnValue(undefined);