dsh-completion-gate: DeepSeek Harness Production Readiness Barrier

`dsh-completion-gate` is a plugin for DeepSeek Harness designed to prevent agents from exiting prematurely when a task is incomplete or has not passed validation. It ensures task quality through two key mechanisms: Premature Stop Protection and Production Readiness Gating. The plugin detects incomplete signals in the code and forces recovery, while collecting machine evidence by automatically detecting test and build commands in ecosystems such as Node.js, Python, Go, and Rust, or by scanning newly added code for TODO/FIXME markers and security vulnerabilities. In addition, it supports agents providing structured completion proofs, and allows the validation process to be controlled strictly or leniently through a configuration center, ensuring that only truly ready code can terminate the task.