nx_audio_lossless_gate.nx

nx_audio_lossless_gate.nx -- MEASURES the two audio-SOTA claims the operator named ("audio where its FLAC but with the dog hearing"): (1) LOSSLESS = bit-exact PCM round-trip through the sovereign LPC codec (the FLAC guarantee: integer linear prediction + exactly-coded residuals, no quantization); (2) WIDE SPECTRUM = a 30kHz "dog whistle" tone (human-inaudible >20kHz, dogs hear to ~45kHz) sampled at 96kHz (Nyquist 48kHz) survives encode->decode UNFILTERED. Three signals stress all codec paths: a voice+ ultrasonic tone mix (the headline), a predictable ramp (the LPC-compresses path), and pseudo-random noise (the raw-fallback path). GREEN iff EVERY signal round-trips bit-exact (max-err = 0) -- proven, not asserted. Reports the compression ratio vs raw PCM (the FLAC comparison). If any max-err != 0 the codec is NOT lossless and this goes RED (measure, don't assume). expect_exit: 0 license_tier: ORIGINAL