dsh-plugin-balance: DeepSeek Harness Web Session Header Balance and Token Usage Plugin

The DSH Web plugin `dsh-plugin-balance` is designed specifically for DeepSeek developers to optimize the account management experience. This plugin adds a balance button to the DSH Web session header, allowing users to view their account balance, current session model, and real-time token usage via a dropdown menu. It automatically estimates costs based on the DeepSeek official pricing, eliminating the need to frequently switch pages to check accounts. Core features include real-time tracking of token consumption in streaming responses; automatic synchronization of the official pricing page every 6 hours, supporting peak/off-peak time adaptation and offline caching to ensure accurate cost estimation; and providing status alerts for low balance and invalid API keys, with support for Chinese-English adaptation. Regarding security, the host side proxies requests to ensure the API Key is not exposed to the browser. Installation requires Node.js.