Initial commit: InstaDrums VST3 drum sampler plugin

- 12-pad drum sampler with 4x3 grid (expandable by 4)
- Velocity layers with round-robin (Salamander-style filename parsing)
- Rhythm Engine-style GUI: pad grid (left), sample editor (right top),
  FX panel (right bottom), master panel (bottom)
- Waveform thumbnails on pads + large waveform in sample editor
- ADSR envelope, pitch, pan per pad
- Drag & drop sample/folder loading
- Kit save/load (.drumkit XML presets)
- Load Folder with smart name matching (kick, snare, hihat, etc.)
- Choke groups, one-shot/polyphonic mode
- Dark modern LookAndFeel with neon accent colors
- Built with JUCE framework, CMake, MSVC 2022

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

Source/SampleEditorPanel.h

@@ -0,0 +1,41 @@
+#pragma once
+#include <JuceHeader.h>
+#include "DrumPad.h"
+#include "WaveformDisplay.h"
+
+class SampleEditorPanel : public juce::Component,
+                          public juce::Slider::Listener
+{
+public:
+    SampleEditorPanel();
+
+    void setPad (DrumPad* pad);
+    DrumPad* getCurrentPad() const { return currentPad; }
+
+    void paint (juce::Graphics& g) override;
+    void resized() override;
+    void sliderValueChanged (juce::Slider* slider) override;
+
+    void updateFromPad();
+
+private:
+    DrumPad* currentPad = nullptr;
+
+    WaveformDisplay waveform;
+
+    // ADSR knobs
+    juce::Slider attackSlider, decaySlider, sustainSlider, releaseSlider;
+    juce::Label  attackLabel, decayLabel, sustainLabel, releaseLabel;
+
+    // Sample controls
+    juce::Slider pitchSlider, panSlider, cutoffSlider, resoSlider;
+    juce::Label  pitchLabel, panLabel, cutoffLabel, resoLabel;
+
+    juce::Label titleLabel { {}, "Sample Editor" };
+    juce::Label padNameLabel { {}, "" };
+
+    void setupKnob (juce::Slider& s, juce::Label& l, const juce::String& name,
+                    double min, double max, double val, double step = 0.01);
+
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (SampleEditorPanel)
+};