feat: Add a dev menu to RCTSurfaceHostingView (2/2) (#2749)

## Summary:

You can launch the dev menu 3 ways:

1. Via the hot key Cmd+D (not supported on macOS at time of writing)
2. Via a right click (which wasn't enabled in Fabric yet)
3. By pressing "d" in metro.

This had a couple of problems:

We don't want to register hotkeys on the window, as a window may have
multiple instances of RN running. We _could_ register it on the root
view. That may be hard to discover as keyboard focus is rarely in the
root view for Mac apps... it's usually just on the window or applicatin.

The right click context menu wasn't available in Fabric, so this PR adds
that. It involves a non trivial amount of code to add a contextContainer
to RCTSurfaceHostingView and have RCTRootViewFactory set it.

The other issue is that when the menu is presented from metro, it's odd
for it to be a context menu off the window or (if it can't find the
window) at coordiantes 0,0 (bottom left of the screen for macOS). To
match other platforms, I think it would be better to make the deve menu
an NSAlert. Let's also preserve the right click context menu for now,
since we don't have a way to get the dev menu from the app without metro
otherwise.


## Test Plan:

Dev menu on Fabric:
<img width="627" height="896" alt="image"
src="https://github.com/user-attachments/assets/50a25f80-db10-4ca3-bbcf-44165d2f4ce8"
/>

Author: Saadnajmi

packages/react-native/Libraries/AppDelegate/RCTRootViewFactory.mm

@@ -33,6 +33,10 @@
 #import <react/renderer/runtimescheduler/RuntimeSchedulerCallInvoker.h>
 #import <react/runtime/JSRuntimeFactory.h>
 
+#if RCT_DEV_MENU // [macOS
+#import "RCTDevMenu.h"
+#endif // macOS]
+
 @implementation RCTRootViewFactoryConfiguration
 
 - (instancetype)initWithBundleURL:(NSURL *)bundleURL newArchEnabled:(BOOL)newArchEnabled
@@ -151,6 +155,14 @@ - (RCTPlatformView *)viewWithModuleName:(NSString *)moduleName // [macOS]
 #if !TARGET_OS_OSX // [macOS]
     surfaceHostingProxyRootView.backgroundColor = [UIColor systemBackgroundColor];
 #endif // [macOS]
+
+#if RCT_DEV_MENU // [macOS
+    RCTDevMenu *devMenu = [self.reactHost.moduleRegistry moduleForClass:[RCTDevMenu class]];
+    if (devMenu) {
+      surfaceHostingProxyRootView.devMenu = devMenu;
+    }
+#endif // macOS]
+
     if (_configuration.customizeRootView != nil) {
       _configuration.customizeRootView(surfaceHostingProxyRootView);
     }
@@ -183,6 +195,16 @@ - (RCTPlatformView *)createRootViewWithBridge:(RCTBridge *)bridge
 {
   BOOL enableFabric = _configuration.fabricEnabled;
   RCTPlatformView *rootView = RCTAppSetupDefaultRootView(bridge, moduleName, initProps, enableFabric); // [macOS]
+  
+#if RCT_DEV_MENU // [macOS
+  if (enableFabric && [rootView isKindOfClass:[RCTSurfaceHostingView class]]) {
+    RCTDevMenu *devMenu = [bridge moduleForClass:[RCTDevMenu class]];
+    if (devMenu) {
+      [(RCTSurfaceHostingView *)rootView setDevMenu:devMenu];
+    }
+  }
+#endif // macOS]
+  
 #if !TARGET_OS_OSX // [macOS]
   rootView.backgroundColor = [UIColor systemBackgroundColor];
 #endif // [macOS]
@@ -327,4 +349,4 @@ - (NSURL *)bundleURL
   return self->_configuration.bundleURLBlock();
 }
 
-@end
+@end

packages/react-native/React/Base/RCTRootView.m

@@ -494,9 +494,9 @@ - (void)containingWindowDidResignKey {
 - (NSMenu *)menuForEvent:(NSEvent *)event
 {
   NSMenu *menu = nil;
-#if __has_include("RCTDevMenu.h") && RCT_DEV
+#if RCT_DEV_MENU
   menu = [[_bridge devMenu] menu];
-#endif
+#endif // RCT_DEV_MENU
   if (menu == nil) {
     menu = [super menuForEvent:event];
   }

packages/react-native/React/Base/Surface/SurfaceHostingView/RCTSurfaceHostingView.h

@@ -14,6 +14,9 @@
 
 @class RCTBridge;
 @class RCTSurface;
+#if RCT_DEV_MENU // [macOS
+@class RCTDevMenu;
+#endif // macOS]
 
 typedef RCTPlatformView *_Nullable (^RCTSurfaceHostingViewActivityIndicatorViewFactory)(void); // [macOS]
 
@@ -63,6 +66,14 @@ NS_ASSUME_NONNULL_BEGIN
  * @param disabled if `YES`, the auto-hide is disabled. Otherwise the loading view will be hidden automatically
  */
 - (void)disableActivityIndicatorAutoHide:(BOOL)disabled;
+
+#if RCT_DEV_MENU // [macOS
+/**
+ * Dev menu for macOS context menu access.
+ */
+@property (nonatomic, strong, nullable) RCTDevMenu *devMenu;
+#endif // macOS]
+
 @end
 
 NS_ASSUME_NONNULL_END

packages/react-native/React/Base/Surface/SurfaceHostingView/RCTSurfaceHostingView.mm

@@ -13,6 +13,10 @@
 #import "RCTSurfaceView.h"
 #import "RCTUtils.h"
 
+#if RCT_DEV_MENU // [macOS
+#import "RCTDevMenu.h"
+#endif // macOS]
+
 @interface RCTSurfaceHostingView ()
 
 @property (nonatomic, assign) BOOL isActivityIndicatorViewVisible;
@@ -134,6 +138,7 @@ - (void)setSizeMeasureMode:(RCTSurfaceSizeMeasureMode)sizeMeasureMode
   _sizeMeasureMode = sizeMeasureMode;
   [self _invalidateLayout];
 }
+
 - (void)disableActivityIndicatorAutoHide:(BOOL)disabled
 {
   _autoHideDisabled = disabled;
@@ -278,4 +283,23 @@ - (void)surface:(__unused RCTSurface *)surface didChangeIntrinsicSize:(__unused
   });
 }
 
+#if TARGET_OS_OSX // [macOS
+
+#pragma mark - Context Menu
+
+- (NSMenu *)menuForEvent:(NSEvent *)event
+{
+#if __has_include("RCTDevMenu.h") && RCT_DEV
+  // Try direct dev menu property first (simplest approach)
+  if (_devMenu) {
+    return [_devMenu menu];
+  }
+  
+
+#endif
+
+  return [super menuForEvent:event];
+}
+#endif // macOS]
+
 @end