luxueliu-reasoning-efforts: Enable gateway models in DSH to select reasoning intensity; one-click level adjustment after upgrade

## Introduction In DSH, the reasoning effort selector only takes effect for ds-series models. If a model connects via a local LLM gateway with manual declarations—for instance, aliases such as gemini3.x, grok, kimi-*, or glm5.x—it neither displays the effort selector nor allows switching the thinking intensity during the conversation. Previously, users could only manually supplement effort declarations for individual models in `~/.dsh/settings.yaml`. However, after a DSH upgrade or when the interface rewrites the settings, these configurations would drift, necessitating repeated rewriting. Below, I introduce the luxueliu-reasoning-efforts plugin. It consolidates the tier configuration into a single source of truth, providing checks and...