refactor(new merge) (#369)

Co-authored-by: paisley <8197966+su8su@users.noreply.github.com>
Co-authored-by: zuolingxuan <zuolingxuan@bytedance.com>

tests/unit/error-model.test.ts

@@ -0,0 +1,26 @@
+import { describe, expect, it } from 'vitest';
+import { AppError, mapBackendErrorCode, normalizeAppError } from '@/lib/error-model';
+
+describe('error-model', () => {
+  it('maps backend UNSUPPORTED to CHANNEL_UNAVAILABLE', () => {
+    expect(mapBackendErrorCode('UNSUPPORTED')).toBe('CHANNEL_UNAVAILABLE');
+  });
+
+  it('normalizes auth errors into AUTH_INVALID', () => {
+    const error = normalizeAppError(new Error('HTTP 401: Invalid Authentication'));
+    expect(error.code).toBe('AUTH_INVALID');
+  });
+
+  it('normalizes ipc channel errors into CHANNEL_UNAVAILABLE', () => {
+    const error = normalizeAppError(new Error('Invalid IPC channel: hostapi:fetch'));
+    expect(error.code).toBe('CHANNEL_UNAVAILABLE');
+  });
+
+  it('preserves AppError and merges details', () => {
+    const base = new AppError('TIMEOUT', 'request timeout', undefined, { a: 1 });
+    const normalized = normalizeAppError(base, { b: 2 });
+    expect(normalized.code).toBe('TIMEOUT');
+    expect(normalized.details).toEqual({ a: 1, b: 2 });
+  });
+});
+