PitchSmoother state not reset on sample rate change

[user1303836]

Problem

When the host calls prepareToPlay (which happens on sample rate changes), PitchSmoother::prepare() (source/dsp/PitchSmoother.h:8-12) only updates sr and calls recomputeAlpha(). It does NOT reset hasValue or smoothed.

This means stale pitch data from a previous sample rate session persists. The smoother will start from whatever frequency it was tracking before the sample rate change, potentially causing a brief glitch or incorrect modulation frequency.

Note: PluginProcessor::prepareToPlay does reset hasValidPitch = false (line 72), but PitchSmoother's internal state remains stale.

Corroborated by: 3/8 audit agents (param-state, stability-edge, pitch-detection)

Suggested Fix

Add state reset to PitchSmoother::prepare():

void prepare(double sampleRate) {
    sr = static_cast<float>(sampleRate);
    hasValue = false;
    smoothed = 0.0f;
    recomputeAlpha();
}

Impact

• Stability: Brief glitch/artifact on sample rate change
• Severity: Medium -- sample rate changes are infrequent but should be handled correctly