Update docs

Author: hwdsl2

README-ja.md

@@ -430,7 +430,7 @@ https://gitlab.com/hwdsl2/setup-ipsec-vpn/-/raw/master/extras/vpnuninstall.sh
 
 ## ライセンス
 
-著作権 (C) 2014-2025 [Lin Song](https://github.com/hwdsl2) [![View my profile on LinkedIn](https://static.licdn.com/scds/common/u/img/webpromo/btn_viewmy_160x25.png)](https://www.linkedin.com/in/linsongui)   
+著作権 (C) 2014-2026 [Lin Song](https://github.com/hwdsl2) [![View my profile on LinkedIn](https://static.licdn.com/scds/common/u/img/webpromo/btn_viewmy_160x25.png)](https://www.linkedin.com/in/linsongui)   
 [Thomas Sarlandieの作品](https://github.com/sarfata/voodooprivacy)に基づく（著作権2012）
 
 [![Creative Commons License](https://i.creativecommons.org/l/by-sa/3.0/88x31.png)](http://creativecommons.org/licenses/by-sa/3.0/)   

README-zh-Hant.md

@@ -430,7 +430,7 @@ https://gitlab.com/hwdsl2/setup-ipsec-vpn/-/raw/master/extras/vpnuninstall.sh
 
 ## 授權條款
 
-版權所有 (C) 2014-2025 [Lin Song](https://github.com/hwdsl2) [![View my profile on LinkedIn](https://static.licdn.com/scds/common/u/img/webpromo/btn_viewmy_160x25.png)](https://www.linkedin.com/in/linsongui)   
+版權所有 (C) 2014-2026 [Lin Song](https://github.com/hwdsl2) [![View my profile on LinkedIn](https://static.licdn.com/scds/common/u/img/webpromo/btn_viewmy_160x25.png)](https://www.linkedin.com/in/linsongui)   
 基於 [Thomas Sarlandie 的工作](https://github.com/sarfata/voodooprivacy)（版權所有 2012）
 
 [![Creative Commons License](https://i.creativecommons.org/l/by-sa/3.0/88x31.png)](http://creativecommons.org/licenses/by-sa/3.0/)   

docs/advanced-usage-zh.md

@@ -260,7 +260,7 @@ sh vpn.sh
 
 ## IPv6 支持
 
-如果你的 VPN 服务器拥有公共（全局单播）IPv6 地址，IKEv2 客户端的 IPv6 支持将在 VPN 安装时自动启用，无需手动配置。
+如果你的 VPN 服务器拥有公共（全局单播）IPv6 地址并且满足以下要求，IKEv2 客户端的 IPv6 支持将在 VPN 安装时自动启用，无需手动配置。
 
 **注：** IPv6 支持已在 Android 上使用 strongSwan VPN 客户端进行测试。其他平台（例如 Windows、macOS、iOS）可能存在限制，或者需要进行额外配置才能使 IPv6 通过 IKEv2 VPN 正常工作。
 

docs/advanced-usage.md

@@ -260,7 +260,7 @@ In the examples above, `VPN_L2TP_LOCAL` is the VPN server's internal IP for IPse
 
 ## IPv6 support
 
-If your VPN server has a public (global unicast) IPv6 address, IPv6 support for IKEv2 clients is automatically enabled during VPN setup. No manual configuration is needed.
+If your VPN server has a public (global unicast) IPv6 address and the requirements below are met, IPv6 support for IKEv2 clients is automatically enabled during VPN setup. No manual configuration is needed.
 
 **Note:** IPv6 support has been tested on Android using the strongSwan VPN client. Other platforms (e.g. Windows, macOS, iOS) may have limitations or require additional configuration for IPv6 to work over the IKEv2 VPN.