Add PUBLIC_SERVER_ID, PUBLIC_RELAY_SERVER, and PUBLIC_API_URL with Settings UI,
unified endpoint resolution across Dashboard/Keys, and fallbacks via PANEL_PUBLIC_HOST.
Updated the documentation for RustDesk mass-deployment, including the correct `--config` deploy string format and the addition of editable client server address fields. Enhanced the dashboard with features like **Copy deploy string** and **Intune script** snippets. Introduced a new environment variable `PANEL_PUBLIC_HOST` for better configuration management. Added UI elements for improved user experience in client configuration.