@choi-p/dsh-deepseek-balance: View DeepSeek balance in the DSH Web sidebar

`@choi-p/dsh-deepseek-balance` is a DSH Web plugin used to display DeepSeek account balances in real-time on the sidebar and supports threshold alerts. The plugin reads the key from the `DEEPSEEK_API_KEY` environment variable, with the Host side handling API requests for security and the Client side managing the interface display. Core features include automatic balance refreshing every 60 seconds, support for displaying only CNY, only USD, or dual currencies, and the ability to set separate alert thresholds for each currency. Configuration changes take effect in real-time without requiring a service restart, and the widget automatically hides when the sidebar is collapsed. Compatible with `dsh >= 0.1.2-alpha.3`, the plugin can be manually installed via the plugin registry or command line. It solves the problem of developers needing to frequently manually query balance.