refactor：项目架构重构和命名规范化

- 统一文件命名为snake_case格式（kebab-case  snake_case）
- 重构zulip模块为zulip_core，明确Core层职责
- 重构user-mgmt模块为user_mgmt，统一命名规范
- 调整模块依赖关系，优化架构分层
- 删除过时的文件和目录结构
- 更新相关文档和配置文件

本次重构涉及大量文件重命名和模块重组，
旨在建立更清晰的项目架构和统一的命名规范。

src/core/security_core/throttle.guard.spec.ts

@@ -0,0 +1,118 @@
+/**
+ * ThrottleGuard 单元测试
+ * 
+ * @author moyin
+ * @version 1.0.0
+ * @since 2026-01-07
+ */
+
+import { Test, TestingModule } from '@nestjs/testing';
+import { ExecutionContext, HttpException, HttpStatus } from '@nestjs/common';
+import { Reflector } from '@nestjs/core';
+import { ThrottleGuard } from './throttle.guard';
+import { ThrottleConfig } from './throttle.decorator';
+
+describe('ThrottleGuard', () => {
+  let guard: ThrottleGuard;
+  let reflector: jest.Mocked<Reflector>;
+
+  beforeEach(async () => {
+    const mockReflector = {
+      get: jest.fn(),
+    };
+
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [
+        ThrottleGuard,
+        { provide: Reflector, useValue: mockReflector },
+      ],
+    }).compile();
+
+    guard = module.get<ThrottleGuard>(ThrottleGuard);
+    reflector = module.get(Reflector);
+  });
+
+  afterEach(() => {
+    jest.clearAllMocks();
+    guard.clearAllRecords();
+  });
+
+  describe('canActivate', () => {
+    it('should allow request when no throttle config is found', async () => {
+      // Arrange
+      reflector.get.mockReturnValue(null);
+      const mockContext = createMockContext();
+
+      // Act
+      const result = await guard.canActivate(mockContext);
+
+      // Assert
+      expect(result).toBe(true);
+    });
+
+    it('should allow first request within limit', async () => {
+      // Arrange
+      const config: ThrottleConfig = { limit: 5, ttl: 60 };
+      reflector.get.mockReturnValueOnce(config).mockReturnValueOnce(null);
+      const mockContext = createMockContext();
+
+      // Act
+      const result = await guard.canActivate(mockContext);
+
+      // Assert
+      expect(result).toBe(true);
+    });
+
+    it('should throw HttpException when limit exceeded', async () => {
+      // Arrange
+      const config: ThrottleConfig = { limit: 1, ttl: 60 };
+      reflector.get.mockReturnValue(config);
+      const mockContext = createMockContext();
+
+      // Act - first request should pass
+      await guard.canActivate(mockContext);
+
+      // Assert - second request should throw
+      await expect(guard.canActivate(mockContext)).rejects.toThrow(HttpException);
+    });
+  });
+
+  describe('getStats', () => {
+    it('should return empty stats initially', () => {
+      const stats = guard.getStats();
+      expect(stats.totalRecords).toBe(0);
+    });
+  });
+
+  describe('clearAllRecords', () => {
+    it('should clear all records', () => {
+      guard.clearAllRecords();
+      const stats = guard.getStats();
+      expect(stats.totalRecords).toBe(0);
+    });
+  });
+
+  describe('onModuleDestroy', () => {
+    it('should cleanup resources', () => {
+      expect(() => guard.onModuleDestroy()).not.toThrow();
+    });
+  });
+
+  function createMockContext(): ExecutionContext {
+    const mockRequest = {
+      ip: '127.0.0.1',
+      method: 'POST',
+      url: '/api/test',
+      route: { path: '/api/test' },
+      get: jest.fn(),
+    };
+
+    return {
+      switchToHttp: jest.fn().mockReturnValue({
+        getRequest: jest.fn().mockReturnValue(mockRequest),
+      }),
+      getHandler: jest.fn(),
+      getClass: jest.fn(),
+    } as any;
+  }
+});