dsh-message-annotator: Adding Citation and Annotation Cards to DeepSeek Harness

`dsh-message-annotator` is a client plugin for DeepSeek Harness designed to enable precise annotations of Agent responses. It supports citing and annotating selected text or full messages, while generated annotation cards can be temporarily stored above the input box. Users can choose to submit annotations together with a draft to the Agent or simply insert the text for review. The plugin offers a bilingual Chinese-English interface, and its data is only valid within the current session.