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/PadComponent.h

@@ -0,0 +1,40 @@
+#pragma once
+#include <JuceHeader.h>
+#include "DrumPad.h"
+
+class PadComponent : public juce::Component,
+                     public juce::FileDragAndDropTarget
+{
+public:
+    PadComponent (DrumPad& pad, std::function<void(int, const juce::File&)> loadCallback, int padIndex);
+
+    void paint (juce::Graphics& g) override;
+    void resized() override;
+
+    void mouseDown (const juce::MouseEvent& event) override;
+    void mouseUp (const juce::MouseEvent& event) override;
+
+    // Drag & Drop
+    bool isInterestedInFileDrag (const juce::StringArray& files) override;
+    void filesDropped (const juce::StringArray& files, int x, int y) override;
+    void fileDragEnter (const juce::StringArray& files, int x, int y) override;
+    void fileDragExit (const juce::StringArray& files) override;
+
+    void setSelected (bool sel) { selected = sel; repaint(); }
+    bool isSelected() const { return selected; }
+
+    // Callback when pad is selected (left click)
+    std::function<void(int)> onSelected;
+
+private:
+    DrumPad& drumPad;
+    std::function<void(int, const juce::File&)> onLoadSample;
+    int index;
+    bool isPressed = false;
+    bool isDragOver = false;
+    bool selected = false;
+
+    void drawWaveformThumbnail (juce::Graphics& g, juce::Rectangle<float> area);
+
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (PadComponent)
+};