dsh-system-control: Sidebar Balance Display and Graceful Shutdown

dsh-system-control is a sidebar plugin designed specifically for DeepSeek Harness (DSH), intended to address the pain points of checking balances and terminating processes. It integrates real-time API balance display and a minimal power shutdown function directly into the left sidebar, without using floating layers, so it does not obstruct or disturb the interface. Balance data refreshes automatically every 25 seconds or can be updated manually with a click, and currency symbols adapt automatically. The shutdown function includes graceful exit with a 1.5-second timeout and forced fallback. The plugin also supports collapsed sidebar adaptation and hiding official icons to keep the interface clean. Installation requires a Git source and depends on the DSH launcher service; currently, only local or Git installation is supported.