dsh-cron-parse: Standard Cron Expression Parsing and Execution Preview Tool

`dsh-cron-parse` is a DeepSeek Harness (DSH) plugin maintained by ZhijiangTang, designed to address scheduled task scheduling needs for AI agents. The plugin adopts a pure ESM module design with zero dependencies and supports standard five-field Cron expressions (minute, hour, day of month, month, and day of week). Its core capabilities include: support for multiple syntax patterns (such as `*`, `*/n`, `a-b`, lists, and names), Vixie-style semantic handling of the “day of month and day of week” union trigger, a mechanism to determine expressions that will never trigger, and daylight saving time calculation. In addition, the plugin provides validation, human-readable Chinese descriptions, expanded field values, and previews of upcoming execution times. After installation, an AI agent can call the `cron_parse` tool by providing parameters such as the Cron expression, repetition count, and time zone.