Initial release — InstaGrain granular synthesizer v1.0

8-voice polyphonic granular synth (VST3/AU/LV2) with:
- 128 grain pool per voice, Hann windowing, linear interpolation
- Root note selector, sample rate correction, sustain pedal (CC64)
- Scatter controls, direction modes (Fwd/Rev/PingPong), freeze
- ADSR envelope, global filter (LP/HP/BP), reverb
- Waveform display with grain visualization
- Drag & drop sample loading, full state save/restore
- CI/CD for Windows/macOS/Linux

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Source/EnvelopePanel.h

@@ -0,0 +1,22 @@
+#pragma once
+#include <JuceHeader.h>
+#include "LookAndFeel.h"
+
+class EnvelopePanel : public juce::Component
+{
+public:
+    EnvelopePanel();
+    void resized() override;
+    void paint (juce::Graphics& g) override;
+
+    juce::Slider attackKnob, decayKnob, sustainKnob, releaseKnob;
+
+private:
+    juce::Label aLabel, dLabel, sLabel, rLabel;
+    juce::Label titleLabel;
+
+    void setupKnob (juce::Slider& knob, juce::Label& label, const juce::String& name,
+                    double min, double max, double def, const juce::String& suffix = "");
+
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (EnvelopePanel)
+};