dsh-model-modes: Inference Modes and Provider-Native Fast Mode for DeepSeek Harness Web Composer

dsh-model-modes is an MIT-licensed plugin (v0.1.3) maintained by DTSFO, designed specifically for the DeepSeek Harness web composer. Its core goal is to add an explicit `Fast ON/OFF` toggle while preserving the reasoning configuration in DSH's official model selector. The plugin addresses the inconsistency of Fast/Priority request parameters across different providers, and strictly ensures that enabling Fast mode does not silently switch models, downgrade reasoning levels, or change providers. It injects provider-native fast parameters at the final `llm-pi-ai` boundary via `AsyncLocalStorage`, supporting `Max + Fast` and `Ul