dsh-team-superflow: Fixed Five-Person Development Team and Spec-Superflow State Machine

`dsh-team-superflow` is a multi-agent collaboration plugin for DeepSeek Harness. Rebuilt from `spec-superflow`, it provides five fixed members (spec writer, architect, engineer, reviewer, and documentation maintainer) and an eight-stage standard workflow. The plugin implements automatic stage progression, build gates, and visualized web tracking, supports creating tasks, managing members, and rolling back processes through commands, and aims to simplify the automated development process from requirements to delivery.