- Parse hackrf_info stderr (newer firmware) and handle non-zero exit codes
- Fix gain_max from 62 to 102 (combined LNA 40 + VGA 62)
- Apply resolved readsb binary path for all SDR types, not just RTL-SDR
- Add HackRF/SoapySDR-specific error messages in ADS-B startup
- Add HackRF waterfall support via rx_sdr IQ capture + FFT
- Add 17 tests for HackRF detection and command builder
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>