oss-prompt-optimizer: Optimizing Raw Instructions in DSH into Structured Prompts

`oss-prompt-optimizer` is a prompt optimization tool within the DSH plugin ecosystem, designed to rewrite brief instructions into professional, structured prompts to address output generalization issues. The plugin operates through harness's LLM service without direct API connections or credential exposure, and it is licensed under MIT. Core functionalities include: providing the `prompt_optimize` tool for agents to support single-time optimization and iterative rewriting; offering a `ctx.promptOptimizer` programming interface for other plugins; integrating a one-click optimization feature in the composer input box; enabling automatic optimization triggered by the `/optimize` prefix (enabled by default, effective only for specific prefixes); and possessing contextual and situational awareness capabilities to automatically inject roles, tasks, and other elements.