dsh-quota-router: DeepSeek Harness Pure-Policy Multi-Source Model Router

`dsh-quota-router` is a purely policy-driven multi-source model routing plugin for DeepSeek Harness (DSH), designed to address the difficulty traditional routing has in distinguishing subtask types by leveraging "task profiles" and "candidate chains." The plugin builds candidate chains using global priorities and mappings, supports health checks, fallback mechanisms, and observability, and is primarily intended for cost source management in mixed workflows. After installation, routing policies are configured through a Web interface to ensure deterministic routing decisions.