dsh-relay-fast: A Relay Enhancement Plugin for DeepSeek Harness

`dsh-relay-fast` is a DeepSeek Harness plugin developed by Rock-ql, designed to simplify relay proxy configuration. It provides three core features: automatic completion of the model `reasoningEfforts` parameter, model list synchronization from the relay, and visual control of Fast priority for model calls (via `service_tier: priority`). Users can customize auto-completion, Fast policies, and default speed through a configuration file. After installation, DSH must be restarted, and the effect of enabling the Fast switch depends on upstream relay support.