@richie.liu/dsh-hybrid-coder: Dual-Model Routing Strategy Plugin

The `@richie.liu/dsh-hybrid-coder` plugin aims to resolve the conflict between resource waste and performance limitations in DeepSeek Harness (DSH) agents. It rewrites request targets to enable dual-model routing: a premium model handles planning and emergencies, while a local small model (e.g., Ollama) executes ordinary steps. Core features include plan-mode upgrades, automatic fallback on consecutive failures, request-level fault recovery, and degradation mechanisms. The plugin is currently experimental and requires specifying premium and local routing parameters in the configuration file.