docs: add PR #3246 to changelog

Author: lbjlaq

README.md

@@ -440,6 +440,11 @@ response = client.chat.completions.create(
 
 *   **版本演进 (Changelog)**:
     *   **v4.4.2 (2026-07-13)**:
+        -   **[核心特性] 增强网页搜索 MCP 集成与网页正文深度读取 (Enhanced Web Search MCP & Content Reading)**:
+            -   **防封锁搜索与容灾**: 重构了搜索词解析与结果排序评分算法，并在官方搜索 API 遭遇限流（Rate Limit）时自动降级采用 DuckDuckGo 的原生 HTML 抓取策略，确保联网搜索永不断联。
+            -   **智能净版正文阅读**: 集成了全新的网页阅读引擎（`handle_web_reader`），搭载 Readability 算法可自动剔除网页中繁杂的导航栏与广告，提取纯净正文并实时转码为易于模型理解的 Markdown 格式。
+            -   **多级智能体衍生派生**: 支持 ZAI 调度引擎允许 AI 智能体直接孵化子级的 MCP 服务器，完成更为复杂的工具链嵌套调用；扩展了底层 `ClientAdapter` 支持更灵活的流转发。
+            -   *相关 PR*: 详见 [PR #3246](https://github.com/lbjlaq/Antigravity-Manager/pull/3246)。
         -   **[核心修复] 彻底解决 Windows 环境下并发卡死与反代页面假死问题 (Tokio Thread Pool Starvation Fix)**:
             -   **隔离高频同步 I/O**: 将后端频繁写入 SQLite 数据库的监控日志从普通的 Tokio 协程中剥离，迁移至原生的 `tokio::task::spawn_blocking` 阻塞线程池中执行。彻底杜绝了 Windows 杀毒软件锁定文件导致的系统级后台阻塞、网络请求中断及应用拒绝响应。
             -   **重构反代页面 CLI 同步锁死问题**: 针对 Windows 版本打开“反代页面”时因 `CliSyncCard` 组件触发检查而导致全客户端冻结的问题，将背后同步执行的 `cmd.exe`、`npm` 等命令行调用（如 `get_cli_sync_status`）以及大批量的账号文件读取统一使用 `spawn_blocking` 和原生 `tokio::fs` 进行改造，页面加载顺滑如初。

README_EN.md

@@ -428,6 +428,11 @@ In clients that support OpenAI protocol (e.g., Cherry Studio), you can configure
 
 *   **Version History (Changelog)**:
     *   **v4.4.2 (2026-07-13)**:
+        -   **[Core Feature] Enhanced Web Search MCP Integration & Deep Content Reading**:
+            -   **Search Resilience & Failover**: Revamped query parsing and result scoring algorithms. Implemented a robust fallback mechanism that automatically utilizes DuckDuckGo HTML scraping when official search APIs hit rate limits, ensuring continuous connectivity.
+            -   **Clutter-Free Reader Engine**: Integrated a powerful web reading engine (`handle_web_reader`) powered by Readability algorithms. It automatically strips ads and navigation noise from webpages, extracting clean main content and converting it to LLM-friendly Markdown on the fly.
+            -   **Nested Agent Server Spawning**: Extended ZAI dispatch to allow AI agents to seamlessly spawn sub-MCP servers for complex nested toolchains. Overhauled `ClientAdapter` to support enhanced stream forwarding.
+            -   *Related PR*: See [PR #3246](https://github.com/lbjlaq/Antigravity-Manager/pull/3246).
         -   **[Core Fix] Completely Resolved Windows Concurrency Freezes and Proxy Page Hangs (Tokio Thread Pool Starvation Fix)**:
             -   **Isolated High-Frequency Sync I/O**: Migrated all synchronous SQLite log writing (`proxy_db::save_log`, `token_stats::record_usage`) out of standard Tokio coroutines and into dedicated `tokio::task::spawn_blocking` thread pools. This entirely eliminates system-wide background blocking, network request interruptions, and application freezes caused by Windows Defender locking database files.
             -   **Refactored Proxy Page CLI Sync Deadlocks**: Addressed a critical bug where opening the "Proxy" page on Windows completely froze the client due to the `CliSyncCard` component triggering synchronous checks. The underlying `cmd.exe` and `npm` system calls (e.g., `get_cli_sync_status`), along with bulk account file reads, have been wrapped in `spawn_blocking` and refactored to use native `tokio::fs`. The page now loads smoothly without locking the async runtime.