DeepSeek Harness Memory Management Plugin: dsh-memento-tab

`dsh-memento-tab` is a session-level memory management plugin for DeepSeek Harness, designed to address the cumbersome nature of command-line management and its side effects. It provides a UI interface that covers the 11 operations of `/memory`, and adds features such as budget monitoring, search filtering, inline rewriting, merging, pending proposals, export/import, and auditing. The plugin does not conflict with upstream and reduces `recall_count` by optimizing the read path. After installation, it appears as the fourth tab at the top of the session, offering a more convenient memory management experience.