dsh-provider-rate-limit: DeepSeek Harness Plugin for Provider/Model-Level Rate Limiting and Gateway Impersonation

The DeepSeek Harness plugin dsh-provider-rate-limit addresses operational challenges such as rate limiting LLM traffic at the provider and model level, managing API quotas, and handling gateway identity verification. Built on the Token Bucket algorithm, the plugin supports burst traffic handling and a FIFO mechanism, and offers dual wait/reject response modes. It also provides gateway identity spoofing by rewriting the User-Agent based on URL matching, and supports configuration hot reloading, real-time statistics, and high-performance route lookup. Developers can view rate-limiting data in the Composer Dock to ensure stable service operation.