GHSA-Q855-8RH5-JFGQ ha-mcp: Add-on settings and policy routes are reachable without authentication at the bare root path

Summary In add-on mode, the ha-mcp settings UI routes are mounted both under the MCP secret path and at the bare root of the published port :9583, so Home Assistant ingress can serve the "Open Web UI" button. The root-mounted routes perform no authentication — no secret, no Origin check, no CSRF...