dsh-issue2pr: End-to-End Delivery from Issue to PR

`dsh-issue2pr` is a global workflow plugin in the DSH ecosystem designed to provide controllability and traceability throughout the Issue-to-PR process. Through an 11-stage pipeline covering analysis, coding, testing, and more, combined with manual gates, an artifact evidence chain, and rollback mechanisms, it transforms automated workflows into an "auditable system." The plugin supports multi-agent collaboration and multiple execution modes, and includes Git hosting integration, a UI workbench, and end-to-end observability. Users need to configure the required connection and initiate execution step by step, ultimately generating PR descriptions and evaluation reports that include detailed background, root-cause analysis, and verification evidence. It is suitable for automated development scenarios that require strict traceability.