Feature: Implement initial macOS SimpleRemoter client

macos/InputHandler.h

@@ -0,0 +1,80 @@
+#pragma once
+
+#import <CoreGraphics/CoreGraphics.h>
+#include <cstdint>
+#include <atomic>
+
+// Windows message constants (for parsing server commands)
+#define WM_MOUSEMOVE      0x0200
+#define WM_LBUTTONDOWN    0x0201
+#define WM_LBUTTONUP      0x0202
+#define WM_LBUTTONDBLCLK  0x0203
+#define WM_RBUTTONDOWN    0x0204
+#define WM_RBUTTONUP      0x0205
+#define WM_RBUTTONDBLCLK  0x0206
+#define WM_MBUTTONDOWN    0x0207
+#define WM_MBUTTONUP      0x0208
+#define WM_MBUTTONDBLCLK  0x0209
+#define WM_MOUSEWHEEL     0x020A
+
+#define WM_KEYDOWN        0x0100
+#define WM_KEYUP          0x0101
+#define WM_SYSKEYDOWN     0x0104
+#define WM_SYSKEYUP       0x0105
+
+// Windows wheel delta extraction
+#define GET_WHEEL_DELTA_WPARAM(wParam) ((short)((wParam) >> 16))
+
+// MSG64 structure (compatible with Windows/Linux)
+#pragma pack(push, 1)
+struct MSG64_MAC {
+    uint64_t hwnd;
+    uint64_t message;
+    uint64_t wParam;
+    uint64_t lParam;
+    uint64_t time;
+    int32_t pt_x;
+    int32_t pt_y;
+};
+#pragma pack(pop)
+
+class InputHandler {
+public:
+    InputHandler();
+    ~InputHandler();
+
+    // Initialize (checks accessibility permission)
+    bool init();
+
+    // Handle input event from server
+    void handleInputEvent(const MSG64_MAC* msg);
+
+    // Check if accessibility permission is available
+    bool hasAccessibilityPermission() const { return m_hasPermission; }
+
+private:
+    // Mouse event helpers
+    void handleMouseMove(int x, int y);
+    void handleMouseButton(CGMouseButton button, bool down, int x, int y);
+    void handleMouseDoubleClick(CGMouseButton button, int x, int y);
+    void handleMouseWheel(int delta);
+
+    // Keyboard event helpers
+    void handleKeyEvent(uint32_t vkCode, bool down);
+
+    // Convert Windows VK code to macOS key code
+    static CGKeyCode vkToMacKeyCode(uint32_t vk);
+
+private:
+    std::atomic<bool> m_hasPermission{false};
+    std::atomic<bool> m_warningLogged{false};
+
+    // Track button states for CGEvent (atomic for thread safety)
+    CGPoint m_lastMousePos;
+    std::atomic<bool> m_leftButtonDown{false};
+    std::atomic<bool> m_rightButtonDown{false};
+    std::atomic<bool> m_middleButtonDown{false};
+
+    // Track modifier key states for proper key event handling
+    std::atomic<CGEventFlags> m_modifierFlags{0};
+};