feat: 重构业务模块架构

- 新增auth模块处理认证逻辑
- 新增security模块处理安全相关功能
- 新增user-mgmt模块管理用户相关操作
- 新增shared模块存放共享组件
- 重构admin模块，添加DTO和Guards
- 为admin模块添加测试文件结构

src/business/admin/tests

@@ -0,0 +1,81 @@
+import { ExecutionContext, UnauthorizedException } from '@nestjs/common';
+import { AdminCoreService, AdminAuthPayload } from '../admin_core/admin_core.service';
+import { AdminGuard } from './admin.guard';
+
+describe('AdminGuard', () => {
+  const payload: AdminAuthPayload = {
+    adminId: '1',
+    username: 'admin',
+    role: 9,
+    iat: 1,
+    exp: 2,
+  };
+
+  const adminCoreServiceMock: Pick<AdminCoreService, 'verifyToken'> = {
+    verifyToken: jest.fn(),
+  };
+
+  const makeContext = (authorization?: any) => {
+    const req: any = { headers: {} };
+    if (authorization !== undefined) {
+      req.headers['authorization'] = authorization;
+    }
+
+    const ctx: Partial<ExecutionContext> = {
+      switchToHttp: () => ({
+        getRequest: () => req,
+        getResponse: () => ({} as any),
+        getNext: () => ({} as any),
+      }),
+    };
+
+    return { ctx: ctx as ExecutionContext, req };
+  };
+
+  beforeEach(() => {
+    jest.resetAllMocks();
+  });
+
+  it('should allow access with valid admin token', () => {
+    (adminCoreServiceMock.verifyToken as jest.Mock).mockReturnValue(payload);
+
+    const guard = new AdminGuard(adminCoreServiceMock as AdminCoreService);
+    const { ctx, req } = makeContext('Bearer valid');
+
+    expect(guard.canActivate(ctx)).toBe(true);
+    expect(adminCoreServiceMock.verifyToken).toHaveBeenCalledWith('valid');
+    expect(req.admin).toEqual(payload);
+  });
+
+  it('should deny access without token', () => {
+    const guard = new AdminGuard(adminCoreServiceMock as AdminCoreService);
+    const { ctx } = makeContext(undefined);
+
+    expect(() => guard.canActivate(ctx)).toThrow(UnauthorizedException);
+  });
+
+  it('should deny access with invalid Authorization format', () => {
+    const guard = new AdminGuard(adminCoreServiceMock as AdminCoreService);
+    const { ctx } = makeContext('InvalidFormat');
+
+    expect(() => guard.canActivate(ctx)).toThrow(UnauthorizedException);
+  });
+
+  it('should deny access when verifyToken throws (invalid/expired)', () => {
+    (adminCoreServiceMock.verifyToken as jest.Mock).mockImplementation(() => {
+      throw new UnauthorizedException('Token已过期');
+    });
+
+    const guard = new AdminGuard(adminCoreServiceMock as AdminCoreService);
+    const { ctx } = makeContext('Bearer bad');
+
+    expect(() => guard.canActivate(ctx)).toThrow(UnauthorizedException);
+  });
+
+  it('should deny access when Authorization header is an array', () => {
+    const guard = new AdminGuard(adminCoreServiceMock as AdminCoreService);
+    const { ctx } = makeContext(['Bearer token']);
+
+    expect(() => guard.canActivate(ctx)).toThrow(UnauthorizedException);
+  });
+});