Add URL validation check to prevent crash

Summary:
Add defensive check to validate the WebSocket URL before attempting to connect.
This prevents potential crashes when an invalid or nil URL is passed to the
WebSocket module, which could cause XPC serialization failures deep in the
network stack.

The crash was observed in  during XPC serialization when
SocketRocket attempted to open a connection with invalid URL data.

Differential Revision:
[to be generated]

D94375527

Author: Vitali Zaidman

packages/react-native/React/CoreModules/RCTWebSocketModule.mm

@@ -10,6 +10,7 @@
 #import <objc/runtime.h>
 
 #import <FBReactNativeSpec/FBReactNativeSpec.h>
+#import <React/RCTAssert.h>
 #import <React/RCTConvert.h>
 #import <React/RCTUtils.h>
 #import <SocketRocket/SRWebSocket.h>
@@ -66,6 +67,14 @@ - (void)invalidate
     connect : (NSURL *)URL protocols : (NSArray *)protocols options : (JS::NativeWebSocketModule::SpecConnectOptions &)
         options socketID : (double)socketID)
 {
+  if ((URL == nil) || URL.absoluteString.length == 0u) {
+    RCTAssert(NO, @"RCTWebSocketModule: Invalid WebSocket URL passed to connect");
+    NSNumber *socketIDNumber = @(socketID);
+    NSDictionary *body = @{@"message" : @"Invalid WebSocket URL", @"id" : socketIDNumber};
+    [self sendEventWithName:@"websocketFailed" body:body];
+    return;
+  }
+
   NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:URL];
 
   // We load cookies from sharedHTTPCookieStorage (shared with XHR and