dsh-web-restart: Add restart button to DSH WebUI, configure launchd auto-restart

dsh-web-restart is a DSH plugin maintained by QIN-SMART (MIT, v0.1.0) designed to address the inconvenience of restarting the WebUI. It consists of two complementary components: the first is the "⇄ Restart DSH" button in the WebUI sidebar, which features a two-step confirmation to prevent accidental clicks. Upon clicking, it triggers the process exit via a same-origin HTTP endpoint, displays a page overlay, and polls every 2 seconds, automatically refreshing once the service is restored; the second is a macOS launchd LaunchAgent daemon that uses KeepAlive to automatically relaunch the process after an exit or crash, with support for login-at-startup. There are two exit modes: the default "exit" mode, which delegates the restart to launchd; and the "exec" mode, which spawns a new instance within the same process, suitable for scenarios without a daemon or manual execution. The installation method is...