dsh-verify-gate: Enforcing Workspace Verification Before Case Closure

The DSH workflow plugin `dsh-verify-gate` is designed to address the issue of case-closing actions failing due to environment state changes during Agent execution. As a pre-execution gate, it requires that the specified verification commands be run in the current workspace before case closure. The workflow can continue only if the verification command executes successfully (exit code 0). This plugin is categorized under workflows, maintained by blueWhalei, and currently has no official installation command or concrete configuration examples. It is suitable for scenarios requiring environment consistency and automated test acceptance.