feat(pkb): Complete PKB module frontend migration with V3 design

Summary:
- Implement PKB Dashboard and Workspace pages based on V3 prototype
- Add single-layer header with integrated Tab navigation
- Implement 3 work modes: Full Text, Deep Read, Batch Processing
- Integrate Ant Design X Chat component for AI conversations
- Create BatchModeComplete with template selection and document processing
- Add compact work mode selector with dropdown design

Backend:
- Migrate PKB controllers and services to /modules/pkb structure
- Register v2 API routes at /api/v2/pkb/knowledge
- Maintain dual API routes for backward compatibility

Technical details:
- Use Zustand for state management
- Handle SSE streaming responses for AI chat
- Support document selection for Deep Read mode
- Implement batch processing with progress tracking

Known issues:
- Batch processing API integration pending
- Knowledge assets page navigation needs optimization

Status: Frontend functional, pending refinement

docs/08-项目管理/PKB迁移-阶段2进行中.md

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+# PKB迁移 - 阶段2进行中
+
+## 🔧 当前问题
+
+**问题**: pkbRoutes导入错误
+**原因**: 使用了命名导出而非默认导出
+
+## ✅ 解决方案
+
+修改 `src/index.ts` 的导入语句：
+
+```typescript
+// ❌ 错误（命名导出）
+import { pkbRoutes } from './modules/pkb/index.js';
+
+// ✅ 正确（默认导出）
+import pkbRoutes from './modules/pkb/routes/index.js';
+```
+
+## 📝 已完成
+- ✅ 创建PKB模块路由入口
+- ✅ 添加健康检查端点
+- ✅ 在主路由注册PKB模块
+- ✅ 修复导入语句
+
+## ⏭️ 下一步
+- 重启服务器测试
+- 验证新旧路由都可用
+
+