3d99cac03b
Add hardware AGC on/off control for SoapySDR backend, wired through the full stack from RigCommand to the web UI: - RigCommand::SetSdrAgc(bool) + ClientCommand::SetSdrAgc in protocol - set_sdr_agc() on RigCat trait (not-supported default) - SoapySdrRig: agc_enabled field, set_sdr_agc() via pipeline agc_cmd, sdr_agc_enabled in filter_state(); removes the "not yet implemented" warning — gain_mode="auto" now properly enables hardware AGC via SoapySDR set_gain_mode() - IqSource::set_gain_mode() trait method; RealIqSource implements it - SdrPipeline: agc_cmd channel, read loop applies it each iteration - POST /set_sdr_agc endpoint in trx-frontend-http - New "SDR settings" full-row in index.html with Hardware AGC checkbox and RF Gain (moved out of WFM controls); row hidden when show_sdr_gain_control is false - app.js: AGC checkbox handler, disables RF gain input while AGC is on, syncs checkbox state from filter.sdr_agc_enabled Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> Signed-off-by: Stan Grams <sjg@haxx.space>