DeepSeek Harness Error Classification and Auto-Retry Plugin

`dsh-better-retry` is a plugin for DeepSeek Harness Web that addresses the issue where certain error codes (such as `PI_AI_ERROR`) are not recognized as rate limits and therefore fail to trigger automatic retries. The plugin reclassifies specific error messages as `RATE_LIMIT`, working together with DSH's retry policy to ensure service stability. Core features include error reclassification, two message matching modes (full match and partial match), a visual management interface, intelligent suggestions, and legacy migration. Users can install it via command, add error entries or test matching rules on the log management page, and precisely control retry behavior.