P4: port framed_render.py model to C++ (FramedDetector: twin-res -> level -> Pchip LUT -> warp -> res^rp gain), replace empirical Detector; tt_base 49.93%->61.45% (single-band); multi-band refs still 100% (model is single-band)

dsp/spectral.hpp

@@ -4,7 +4,7 @@
 #include <complex>
 #include <vector>
 #include "fft.hpp"
-#include "detect.hpp"
+#include "framed_model.hpp"
 
 constexpr size_t DEFAULT_NFFT = 2048;
 constexpr size_t DEFAULT_HOP = 512;
@@ -14,7 +14,7 @@ public:
     SpectralProcessor(size_t nfft = DEFAULT_NFFT, size_t hop = DEFAULT_HOP);
     ~SpectralProcessor();
 
-    void setDetectorParams(float sharpness, float selectivity, float depth);
+    void setDetectorParams(float fc, float q);
     void processBlock(float* in, float* out, size_t num_samples, size_t num_channels = 1);
 
 private:
@@ -26,7 +26,7 @@ private:
     std::complex<double>* tmp_buf_;
     std::vector<float> overlap_;
     std::vector<float> mask_;
-    Detector detector_;
+    FramedDetector detector_;
     size_t frame_count_;
     size_t output_pos_;