dsh-md-annotator: Annotate and write modification instructions in the DSH sidebar Markdown preview

`dsh-md-annotator` is a DSH Web plugin that depends on `dsh-better-sidebar` and is used to annotate items one by one in Markdown preview and generate structured modification instructions. It supports adding insert, modify, and delete annotations to blocks such as headings, paragraphs, and lists, or selected text, and allows marking priorities. The plugin provides a visual annotation list panel that supports locating, batch management, and JSON export backup. Users can send annotations to the chat input box as structured instructions containing file paths, line numbers, and original text quotes, either in a single action or in batches, to facilitate model execution of modifications. If the file is regenerated, the plugin will re-match the annotations and mark the changes. Annotations are stored only in browser memory and are cleared after restarting or disabling the plugin. The plugin takes over the Markdown sidebar preview and provides source code editing support, but the built-in edit mode is unavailable. Requires Node...