DSH Landscape: Pre-check for Read-only Capabilities of DeepSeek Harness

`cyanseek/dsh-landscape` is a read-only capability pre-check tool specifically designed for DeepSeek Harness (DSH). It aims to address the pain points developers face when adding or developing plugins, such as the lack of a unified pre-check entry point and the need for manual comparisons between codebases and runtime behaviors. By accepting natural language change requests as input, this tool outputs fact-based decision recommendations (such as whether to use, install, build, or wait) based on the current environment, ecosystem evidence, and constraints, while clearly indicating the safest next step. Its core features include: strictly read-only, never performing any modification operations like installation, upgrade, or configuration changes; zero-cost configuration, requiring no API keys or accounts; and structured results, providing `decision`, `nextAction`, `risks`, and `doNotBuild`/`buildOnly` recommendations.