Add macOS default file loader, windows WIP

src/app/core/platform/file_dialog.h

@@ -0,0 +1,58 @@
+#include <string>
+
+#ifdef _WIN32
+// Include Windows-specific headers
+#include <shobjidl.h>
+#include <windows.h>
+
+std::string ShowOpenFileDialog() {
+  CoInitializeEx(NULL, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE);
+
+  IFileDialog *pfd = NULL;
+  HRESULT hr =
+      CoCreateInstance(CLSID_FileOpenDialog, NULL, CLSCTX_ALL, IID_IFileDialog,
+                       reinterpret_cast<void **>(&pfd));
+
+  if (SUCCEEDED(hr)) {
+    // Show the dialog
+    hr = pfd->Show(NULL);
+    if (SUCCEEDED(hr)) {
+      IShellItem *psiResult;
+      hr = pfd->GetResult(&psiResult);
+      if (SUCCEEDED(hr)) {
+        // Get the file path
+        PWSTR pszFilePath;
+        psiResult->GetDisplayName(SIGDN_FILESYSPATH, &pszFilePath);
+        psiResult->Release();
+        CoTaskMemFree(pszFilePath);
+      }
+    }
+    pfd->Release();
+  }
+
+  CoUninitialize();
+  return L"";  // Return an empty string if no file was selected or an error
+}
+
+#elif defined(__APPLE__)
+
+#include <string>
+
+class FileDialogWrapper {
+ public:
+  static std::string ShowOpenFileDialog();
+};
+
+
+#elif defined(__linux__)
+#include <gtk/gtk.h>
+
+std::string ShowOpenFileDialog() {
+  // Linux-specific file dialog implementation using GTK
+  // ...
+  return "file_path_linux";
+}
+
+#else
+#error "Unsupported platform."
+#endif

src/app/core/platform/file_dialog.mm

@@ -0,0 +1,17 @@
+#import <Cocoa/Cocoa.h>
+#include "app/core/platform/file_dialog.h"
+
+std::string FileDialogWrapper::ShowOpenFileDialog() {
+  NSOpenPanel* openPanel = [NSOpenPanel openPanel];
+  [openPanel setCanChooseFiles:YES];
+  [openPanel setCanChooseDirectories:NO];
+  [openPanel setAllowsMultipleSelection:NO];
+
+  if ([openPanel runModal] == NSModalResponseOK) {
+    NSURL* url = [[openPanel URLs] objectAtIndex:0];
+    NSString* path = [url path];
+    return std::string([path UTF8String]);
+  }
+
+  return "";
+}