dsh-plugin-factory: Allowing Agents in DSH Sessions to Write Plugins Themselves

# Introduction If you are developing plugins for DeepSeek Harness (dsh), you will encounter a practical issue: dsh plugins are bound by strict contract specifications, such as the `apply(ctx)` lifecycle function, `defineTool` tool definitions, and hard constraints in the Schema DSL. These APIs require users to consult documentation, and are even more cumbersome for models. Since dsh was released not long ago, models lack specific training data. Simply prompting an Agent in a session with "Help me create a XX plugin" can easily lead to API hallucinations, resulting in non-functional code. dsh-plugin-factory is designed to solve this exact problem: it provides a complete plugin development toolchain for Agents within dsh sessions, enabling...