Implement HF radiofax decoding with custom Python DSP pipeline
(rtl_fm USB → Goertzel/Hilbert demodulation), 33-station database
with broadcast schedules, audio waveform scope, live image preview,
and decoded image gallery. Amber/gold UI theme for HF distinction.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
