dsh-web-search-pool: A Multi-Vendor Search Key Pool for DeepSeek Harness

`dsh-web-search-pool` is a multi-provider search load-balancing plugin designed specifically for DeepSeek Harness, aimed at solving the problem of `web_search` tool interruptions caused by rate limiting (429), quota exhaustion, or network errors on a single API Key. The plugin supports unified management of multiple Tavily and Exa API Keys, builds a search Key pool, and performs scheduling based on RPM-weighted round-robin. When a Key becomes unavailable, the system automatically switches to the next available Key, ensuring the stability of the search service. Its core advantages include: securely storing API Keys through the DSH credentials service, avoiding plaintext writing into configuration files; providing a visualization interface for viewing quotas and limits in real time; and a built-in