Ground Station: Unauthenticated out-of-containment file read via `sigmfplayback` `recordingPath`

Ground Station is a browser-based suite for satellite tracking, SDR reception, hardware control, and telemetry decoding. Prior to version 0.4.13, the unauthenticated configure-sdr Socket.IO command accepts a recordingPath for the sigmf-playback SDR and backend/handlers/entities/sdr.py stores it without validation before backend/hardware/sigmfprobe.py opens the path without enforcing containment. An absolute path or parent-directory escape ending in .sigmf-meta is parsed as JSON and returned in reply["data"]["metadata"] by the get-sdr-parameters flow. Exploitation requires the metadata file to be readable JSON and to have a sibling .sigmf-data file, but it can disclose contents outside backend/data/recordings without authentication. This issue is fixed in version 0.4.13.