KB: audio fidelity Phase 1+2 settled facts -> context/wintesla-port.md

wPreset patch numbering, SF2 v1.0 pitch generators + EMU8000 44100 base rate +
the WAV bake formula, inverted SBK attenuation, full-zone/key-select/loop-
region/release-fade architecture, distance/gain/doppler model, the audio-clock
origin (FUN_0044e19c = ApplicationManager::GetFrameRate; frames were clock
ticks), and the ConfigureActivePress base-attribute resolution.  Annotated the
mech4.cpp velocity smoothing as AUTHENTIC [T1] (binary Mech::Execute AverageOf
filters, part_012.c:15169-15179).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

game/reconstructed/mech4.cpp

@@ -3647,6 +3647,10 @@ void
 			// Start/Stop-flapped the engine ambience on every footfall (heard as a
 			// static tick per step).  ~0.25s exponential filter kills the stride
 			// ripple while tracking real speed changes within a couple of strides.
+			// AUTHENTIC [T1]: the binary's Mech::Execute (FUN_004ab430) runs the
+			// localVelocity components through AverageOf running-average filters
+			// (part_012.c:15169-15179) -- the original smoothed the published
+			// velocity the same way; this filter reconstructs that stage.
 			{
 				Scalar alpha = dt / (dt + 0.25f);
 				fwdSpeedFiltered  += alpha * (fwdSpeed - fwdSpeedFiltered);