refactor(erp-auth): implement precise login result detection with three outcomes

- Add waitForLoginResult() method using Promise.race to detect:
  - Success: .nc-workbench-icon element visible
  - Failure: '名称或密码错误' error text visible
  - Force login: click confirm button and re-detect
- Extract timeout constants (PAGE_LOAD_TIMEOUT, LOGIN_RESULT_TIMEOUT, FORCE_LOGIN_TIMEOUT)
- Improve error handling with clear error messages
- Add unit tests for class structure verification
- Fix test setup for Electron app mock

Fixes: ERP login success/failure detection was ambiguous

tests/setup.ts

@@ -1,7 +1,17 @@
-import { beforeAll, afterAll } from 'vitest'
+import { beforeAll, afterAll, vi } from 'vitest'
 import dotenv from 'dotenv'
 import path from 'path'
 
+// Mock electron app module for unit tests
+vi.mock('electron', () => ({
+  app: {
+    isPackaged: false,
+    isReady: vi.fn().mockReturnValue(false),
+    getPath: vi.fn().mockReturnValue(path.join(process.cwd(), 'logs')),
+    on: vi.fn()
+  }
+}))
+
 // Load environment variables from project root
 dotenv.config({ path: path.resolve(process.cwd(), '.env') })