DeepSeek Harness ServerChan Push Assistant Plugin

When DeepSeek Harness (DSH) is waiting for manual intervention, closing the browser means no reminders will be received. This plugin fills that gap by monitoring the host-side event stream and sending mobile push notifications via ServerChan after a timeout. It supports the `ask_user_question`, `exit_plan_mode`, and `approval/asked` scenarios, and can restore timers after a restart while storing the SendKey locally with AES-256-GCM encryption. Users only need to install the plugin and configure the SendKey, push threshold, and link to receive timely pending-task notifications on their computer or mobile device.