dsh-ci-doctor: Monitoring GitHub Actions Failures and Generating Structured Diagnostics

`dsh-ci-doctor` is a DeepSeek Harness (DSH) plugin designed to address the pain point of tedious log analysis after GitHub Actions failures. The plugin provides two core capabilities: monitoring and diagnosis. Through `ci_watch`, it launches a background task that polls for new failed runs and sets a baseline to avoid false positives from historical failures; through `ci_diagnose`, it transforms raw logs into structured findings, generating a Markdown diagnostic card containing normalized error signatures, failure categories, and suspicious files. The plugin strictly adheres to a read-only contract, only reading GitHub states without performing write operations such as pushing, merging, or re-running. It relies on an authenticated GitHub CLI session and supports starting monitoring or diagnosing specified runs via natural language instructions. In addition, the plugin features signature