Blueprint Studio terminal SSH private key written to disk

Blueprint Studio is a VS Code-like file editor for Home Assistant configuration files. Prior to 2.5.2, Blueprint Studio terminal SSH key authentication in custom_components/blueprint_studio/backend/terminal_manager.py wrote SSH private-key material to a file under the Home Assistant configuration directory before applying restrictive permissions and relied on best-effort cleanup. The key could temporarily remain on disk and could persist if cleanup failed or Home Assistant crashed. A user or process with filesystem access to the Home Assistant configuration directory could obtain the residual private key. This issue is fixed in version 2.5.2.