dsh-home-assistant-panel: Offload Home Assistant environment baseline to DSH session

dsh-home-assistant-panel is a DeepSeek Harness client plugin written by maintainer hotkong. It injects the Home Assistant address, version, and runtime status into the system prompt via a one-time configuration, and provides a read-only status card and a `ha_status` tool. The article introduces its four entry points, installation commands, configuration options, and access token handling, and explains its read-only boundaries, security design, and common troubleshooting.