dsh-ci-context: A Privacy-First CI Execution Context Plugin for DeepSeek Harness

`dsh-ci-context` is a privacy-first plugin for DeepSeek Harness, designed to securely provide agents in CI pipelines with execution context. It addresses privacy leakage and performance overhead issues in traditional methods by reading only whitelisted, non-sensitive environment variables in the first step—such as repository, trigger type, and commit SHA—and generating a metadata snapshot. The plugin supports GitHub Actions, GitLab CI, and a generic fallback, with automatic deduplication and strict privacy controls.