Introduces the trx-backend-soapysdr crate with a compilable SoapySdrRig
struct that satisfies the Rig + RigCat trait bounds. RX methods
(get_status, set_freq, set_mode, get_signal_strength) are implemented;
TX-only methods return RigError::not_supported. as_audio_source returns
None for now (overridden in SDR-07). Wires the crate into the workspace
and trx-backend (feature "soapysdr"), and fixes the non-exhaustive match
on RigAccess::Sdr in trx-server main.rs and rig_task.rs.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>
Add `RigAccess::Sdr { args: String }` to the backend access enum, register
a feature-gated `soapysdr` factory stub in `register_builtin_backends_on`,
handle the new variant in all existing `match` arms, and add the `soapysdr`
feature flag (no dep yet; implementation lands in SDR-04). Mark SDR-02 done.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>
Move the frontend and backend crate trees to live physically under their
respective binary crate directories, grouping related code together
without merging crate boundaries. Also flatten sub-crate nesting by
moving them out of src/ subdirectories into direct children.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>