dsh-quota-overview: Add DeepSeek balance and OpenCode Go usage to sidebar

This article introduces the DSH Web plugin, dsh-quota-overview, maintained by joyboy-yy. It adds a dedicated "Quota" row at the bottom of the sidebar, displaying the DeepSeek account balance alongside OpenCode Go usage metrics (5 hours/weekly/monthly). Clicking the entry opens a detailed popup window that allows users to view usage details, reset the countdown, or input an API Key directly if it is missing. The article covers the plugin's functionality, key parsing order, data sources, installation commands, and applicable scenarios.