feat(server): 添加可插拔认证系统 | add pluggable authentication system (#386)

* feat(server): 添加可插拔认证系统 | add pluggable authentication system

- 新增 JWT 认证提供者 (createJwtAuthProvider)
- 新增 Session 认证提供者 (createSessionAuthProvider)
- 新增服务器认证 mixin (withAuth)
- 新增房间认证 mixin (withRoomAuth)
- 新增认证装饰器 (@requireAuth, @requireRole)
- 新增测试工具 (MockAuthProvider)
- 新增中英文文档
- 导出路径: @esengine/server/auth, @esengine/server/auth/testing

* fix(server): 使用加密安全的随机数生成 session ID | use crypto-secure random for session ID

docs/astro.config.mjs

@@ -267,6 +267,7 @@ export default defineConfig({
                 { label: '概述', slug: 'modules/network', translations: { en: 'Overview' } },
                 { label: '客户端', slug: 'modules/network/client', translations: { en: 'Client' } },
                 { label: '服务器', slug: 'modules/network/server', translations: { en: 'Server' } },
+                { label: '认证系统', slug: 'modules/network/auth', translations: { en: 'Authentication' } },
                 { label: '状态同步', slug: 'modules/network/sync', translations: { en: 'State Sync' } },
                 { label: '客户端预测', slug: 'modules/network/prediction', translations: { en: 'Prediction' } },
                 { label: 'AOI 兴趣区域', slug: 'modules/network/aoi', translations: { en: 'AOI' } },