dsh-models-filter: A Model Menu Filtering Plugin for DeepSeek Harness

The `odelbos/dsh-models-filter` plugin adds model filtering to the DeepSeek Harness Web interface. Users can filter models case-insensitively by name, ID, or provider through the top input field. It supports keyboard navigation (↑↓ to select, Enter to confirm, Esc to clear) and maintains consistency with the original menu design. The plugin requires DSH version `0.1.1-rc.2` and is licensed under the MIT License.