DSH Diff Text Comparison Tool Plugin: dsh-tool-diff

dsh-tool-diff is a read-only text diff tool within the DSH plugin system, supporting structured comparison of text, JSON, CSV, and Markdown, and generating unified diffs. The tool features pure functions and zero dependencies, with all operations completed entirely in memory and never written to disk. Users must install it to a target profile (such as headless or web) via the `dsh plugin` command, noting that different profiles require independent installation. When invoking it, specify the action type and the before-and-after content, with optional format and primary key parameters. The output is a standard JSON envelope, containing equality status, truncation status, byte count, and a change list. This tool is suitable for scenarios requiring safe comparison of configurations, API responses, or document revisions, but it is subject to a 256 KiB limit on each side of the input.