dsh-model-reasoning: Auto-Populate Reasoning and Context Parameters for Unofficial Models

`dsh-model-reasoning` is a DeepSeek Harness plugin designed to address missing configurations for unofficial model providers. It automatically populates key model parameters, such as reasoning level, context window, output limit, and image modality, and configures routing compatibility. The plugin supports provider exclusion and offline caching, taking effect automatically after installation. It requires DSH 0.1.2-rc.1, significantly lowering the barrier to integrating unofficial models.