dsh-wallpaper-position: A Wallpaper Position Fine-Tuning Plugin for dsh-dream-skin

`dsh-wallpaper-position` is a satellite plugin designed for DeepSeek Harness (DSH), intended to resolve the issue where the default wallpaper in `dsh-dream-skin` is centered and obstructs the chat area. The plugin provides pixel-level displacement control on the frontend via CSS variables, supporting ±5000px adjustments along the X and Y axes, and retains position memory keyed by wallpaper hash. Users can fine-tune the background position in the settings using quick buttons or numeric inputs, with the corresponding remembered position automatically restored when switching images. This plugin depends on `dsh-dream-skin`, supports only displacement, and may carry potential Host compatibility risks or conflict with other background plugins.