dsh-erii-boot-splash: Sakura-Themed Boot Animation for DeepSeek Harness Web UI

`dsh-erii-boot-splash` is a boot animation plugin for DeepSeek Harness based on the Erii theme. It replaces the default loading interface with animations—such as falling cherry blossoms, a mint-colored mascot, and a pulsing title—displayed at Web UI startup. The plugin is implemented entirely on the client side with zero runtime dependencies; it takes effect after restarting the service following installation, and developers can customize animation details by modifying the configuration file.