dsh-auto-successor: Automatically start a new successor session when the DSH session count reaches the threshold.

`dsh-auto-successor` (automatic handover) automatically creates a new session when the DSH session context window exceeds a threshold: the AI summarizes the task status into a five-point handover draft and writes it into the first message of the new session, while also allowing the archiving of the old session. Unlike in-place compression, it preserves full history and initiates a fresh context. Based on the official README, this article explains installation commands, panel rules, the global tools `successor_handoff`/`successor_status`, the data directory, and known limitations, making it suitable for workflow scenarios involving long tasks without interruption.