dsh-plugin-doctor: DeepSeek Harness Plugin Health Check

dsh-plugin-doctor is a plugin health check tool in the DeepSeek Harness (DSH) ecosystem, corresponding to RFC #1629. It provides CLI and Agent-callable interfaces for verifying the integrity of manifest, patch, entry, build, pack, install, and config before plugin release. Core features include host masking, dependency, and native module checks against DSH profiles, as well as heuristic security audits (e.g., pre-side effects, Shell launcher risks). The tool supports read-only audit modes (audit/audit-batch), can generate JSON or Markdown reports, is suitable for CI integration, and offers environment diagnostics.