docs: mention Windows Defender loopback issue

docs/installation.md

@@ -160,6 +160,12 @@ type ga
 
 If it resolves to something unexpected, do not rely on the shortcut. Run GA from the install directory with `python launch.pyw` or `python frontends/tuiapp_v2.py`.
 
+#### Windows Defender blocks local loopback
+
+The desktop app talks to its local bridge over `127.0.0.1` / `localhost`. On some Windows machines, Windows Defender Firewall may block this loopback connection, making the desktop app look like it cannot start or cannot connect to the service.
+
+If this happens, allow `GenericAgent.exe` and the bundled `python.exe` through Windows Defender Firewall, then restart the desktop app.
+
 #### Windows TUI rendering issues
 
 TUI rendering on Windows depends on terminal, font, and `textual` version.

docs/installation_zh.md

@@ -160,6 +160,12 @@ type ga
 
 如果解析到意料之外的位置，就不要依赖这个快捷命令。请进入安装目录运行 `python launch.pyw` 或 `python frontends/tuiapp_v2.py`。
 
+#### Windows Defender 拦截本机回环网络
+
+桌面端会通过 `127.0.0.1` / `localhost` 连接本机 bridge 服务。部分 Windows 机器上，Windows Defender 防火墙可能会拦截这个本机回环连接，导致桌面端看起来无法启动，或一直连不上服务。
+
+如果遇到这种情况，请在 Windows Defender 防火墙中允许 `GenericAgent.exe` 和随包的 `python.exe` 通过，然后重启桌面端。
+
 #### Windows 上 TUI 显示异常
 
 TUI 在 Windows 上依赖终端、字体和 `textual` 版本。