dsh-plugin-gpt-load: Integrating the gpt-load Model Pool into DeepSeek Harness

The `dsh-plugin-gpt-load` plugin for DSH (DeepSeek Harness) addresses the limitation of the native architecture in handling protocols at the first-level provider routing, enabling mixed use of OpenAI and Anthropic protocols within a single group. It provides features such as single-group display, automatic model-pool synchronization, automatic capability population, and secure key storage. Users can enable it by running the installation command and configuring the gateway address and AccessKey. The plugin supports manually specifying the protocol or automatic detection in settings, and automatically handles compatibility with older routing versions.