@dsh-external/dsh-inspect: Adding checkup / fix / review closed loop for DSH

@dsh-external/dsh-inspect is a DSH plugin designed to construct a closed-loop process of "problem identification → repair delivery → quality review" by providing three tools: checkup, fix, and review. The checkup tool is used to inspect code and output a graded issue list, combined with red team verification to ensure that issues are reproducible. The fix tool performs repairs based on the issue list, employing parallel implementation and adversarial checking mechanisms, and outputs a delivery report. The review tool then conducts a retrospective review of the deliverables, supporting item-by-item re-running verification to ensure that the fixed issues have truly been eliminated. These three tools can be used independently or chained together to form an automated closed-loop, where feedback from a failed review can be fed back to the fix tool for further iteration. The plugin is built upon the DSH workflow engine and schemastery, and does not register into ctx.ski.