dsh-task-orchestrator: Automated Plan-First Task Orchestration

`dsh-task-orchestrator` is a plugin designed for DeepSeek Harness (DSH) to automate task decomposition and dependency management in complex workflows. It adopts a plan-first mechanism that allows the parent model to create and assign TODO plans, then processes long-chain tasks efficiently using dependency-aware queues and isolated execution environments. The plugin supports single-agent and multi-agent parallelism and provides state snapshot functionality for workflow recovery. After installation and enablement, it is well suited to complex scenarios involving coordinated subtasks with dependencies, significantly improving processing efficiency and accuracy.