[feat] add controller info and file transfer in server window

src/common/window_util_mac.mm

@@ -0,0 +1,64 @@
+#include "window_util_mac.h"
+
+#if defined(__APPLE__)
+
+#include <SDL3/SDL.h>
+
+#import <Cocoa/Cocoa.h>
+
+namespace crossdesk {
+
+static NSWindow* GetNSWindowFromSDL(::SDL_Window* window) {
+  if (!window) {
+    return nil;
+  }
+
+#if !defined(SDL_PROP_WINDOW_COCOA_WINDOW_POINTER)
+  return nil;
+#else
+  SDL_PropertiesID props = SDL_GetWindowProperties(window);
+  void* cocoa_window_ptr =
+      SDL_GetPointerProperty(props, SDL_PROP_WINDOW_COCOA_WINDOW_POINTER, NULL);
+  if (!cocoa_window_ptr) {
+    return nil;
+  }
+  return (__bridge NSWindow*)cocoa_window_ptr;
+#endif
+}
+
+void MacSetWindowAlwaysOnTop(::SDL_Window* window, bool always_on_top) {
+  NSWindow* ns_window = GetNSWindowFromSDL(window);
+  if (!ns_window) {
+    (void)always_on_top;
+    return;
+  }
+
+  // Keep above normal windows.
+  const NSInteger level = always_on_top ? NSFloatingWindowLevel : NSNormalWindowLevel;
+  [ns_window setLevel:level];
+
+  // Optional: keep visible across Spaces/fullscreen. Safe as best-effort.
+  NSWindowCollectionBehavior behavior = [ns_window collectionBehavior];
+  behavior |= NSWindowCollectionBehaviorCanJoinAllSpaces;
+  behavior |= NSWindowCollectionBehaviorFullScreenAuxiliary;
+  [ns_window setCollectionBehavior:behavior];
+}
+
+void MacSetWindowExcludedFromWindowMenu(::SDL_Window* window, bool excluded) {
+  NSWindow* ns_window = GetNSWindowFromSDL(window);
+  if (!ns_window) {
+    (void)excluded;
+    return;
+  }
+
+  [ns_window setExcludedFromWindowsMenu:excluded];
+
+  NSWindowCollectionBehavior behavior = [ns_window collectionBehavior];
+  behavior |= NSWindowCollectionBehaviorIgnoresCycle;
+  behavior |= NSWindowCollectionBehaviorTransient;
+  [ns_window setCollectionBehavior:behavior];
+}
+
+}  // namespace crossdesk
+
+#endif  // __APPLE__