dsh-balance: Permanently Monitor DeepSeek Balance and OpenCodeGo Quota in dsh Web

`dsh-balance` is a persistent plugin for `dsh web`, designed to simultaneously display the balance of the DeepSeek API account and the remaining quota of the OpenCodeGo plan. This plugin is open-source under the MIT license and maintained by linshule. Its core features include a draggable and position-memory badge in the lower-left corner, a click-to-expand details layer (containing a progress bar and reset time), and a standalone settings page. Users can manage the DeepSeek API Key (persisted locally with 0600 permissions) and the OpenCodeGo Key (defaulting to reading from credentials or manually specifying). The plugin supports automatic data refresh at set intervals (default 1 minute) and automatic retries during network jitter. Installation requires adding the plugin first and then restarting `dsh web`, with support for installing from GitHub or locally.