Extend the RDS feature set with LPS and eRT support, add initial RDS2/logo-transfer wiring, update the control UI and refresh the PlutoSDR example configuration and reference docs.

Extend the RDS stack with TP/TA live updates, CT, RT+, PTYN, AF and EON support, and add UI/config controls for the new RDS feature set.

Keep DSP state persistent across generated frames, move the RDS encoder to arbitrary sample-rate operation, and tune the Pluto profile to the working 2.28 MHz path with the levels that finally decode reliably.