1be5b3d4c2
Replace the stub SoapySdrRig with a full implementation: wire up SdrPipeline from dsp.rs, implement AudioSource::subscribe_pcm on the primary channel, add gain control (manual/auto with fallback warning), and track primary channel freq/mode so set_freq/set_mode update the live DSP pipeline. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> Signed-off-by: Stan Grams <sjg@haxx.space>