PaperPhonePlus Android 2.6.5

• Added friend requests and mutual removal from user profiles. Refresh friends on WebSocket authentication and friendship changes, and refresh pending requests when the relationship changes.

• Group messages use signed Sender Key encryption with server-published member keys. New group messages no longer use the text-appearance password layer. Earlier group messages still support their original appearance password.

• Updated Android, package metadata, and the profile footer to 2.6.5 (versionCode 26005). Release builds restrict native libraries to arm64-v8a.

• 用户资料页支持发送好友申请和双向删除好友。连接认证或好友关系变更时刷新好友列表，关系变更时也刷新待处理申请。

• 群聊使用服务端公布的成员公钥分发 Sender Key，并校验消息签名。新群消息直接走群加密，旧文本外观密文仍可用原密码读取。

• Android 原生版本、包元数据和个人信息页底部统一为 2.6.5（versionCode 26005）。正式构建的原生库仅允许 arm64-v8a。

已有单向好友记录的修复需要部署包含 d3e95fe 和 0d65d79 的上游服务端。