重构network库（mvp版本）搭建基础设施和核心接口

定义ITransport/ISerializer/INetworkMessage接口
NetworkIdentity组件
基础事件定义

packages/network-server/jest.config.cjs

@@ -1,7 +1,7 @@
 /** @type {import('ts-jest').JestConfigWithTsJest} */
 module.exports = {
   preset: 'ts-jest',
-  testEnvironment: 'node', // 服务端库使用 node 环境
+  testEnvironment: 'node',
   roots: ['<rootDir>/tests'],
   testMatch: ['**/*.test.ts', '**/*.spec.ts'],
   testPathIgnorePatterns: ['/node_modules/'],
@@ -18,16 +18,10 @@ module.exports = {
   coverageReporters: ['text', 'lcov', 'html'],
   coverageThreshold: {
     global: {
-      branches: 60,
+      branches: 70,
       functions: 70,
       lines: 70,
       statements: 70
-    },
-    './src/core/': {
-      branches: 70,
-      functions: 80,
-      lines: 80,
-      statements: 80
     }
   },
   verbose: true,
@@ -42,7 +36,7 @@ module.exports = {
   },
   moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
   setupFilesAfterEnv: ['<rootDir>/tests/setup.ts'],
-  testTimeout: 10000,
+  testTimeout: 15000, // 服务端测试可能需要更长时间
   clearMocks: true,
   restoreMocks: true,
   modulePathIgnorePatterns: [