ACI: the hard limiter in channel.rs normalised IQ samples to unit
magnitude *before* the CMA equalizer, making the signal perfectly
constant-modulus so the CMA never adapted and tap deviation stayed
at zero. Fix by moving the hard limiter inside process_iq (after
the CMA) and replacing the CMA-based metric with IQ envelope
coefficient of variation, computed on the raw samples.
CCI: the pilot coherence has a theoretical maximum of π/4 ≈ 0.785
(not 1.0), so coherence_penalty was always ~0.215 even for a clean
signal. The Q/I ratio also depended on the arbitrary NCO-pilot
phase offset rather than actual interference. Fix by normalising
coherence by its theoretical max and dropping the phase-dependent
Q/I ratio. Gate CCI on pilot detection so mono signals read 0%.
https://claude.ai/code/session_01PUXWNMRGfrWYH56k2DLmen
Signed-off-by: Claude <noreply@anthropic.com>
