fix(companion): synthesize gestures synchronously to avoid the async completion crash

companion/Sources/Gesture.swift

@@ -73,17 +73,9 @@ enum Gesture {
         let record = XCSynthesizedEventRecord(name: "companion", interfaceOrientation: 0)
         record.add(path)
 
-        let semaphore = DispatchSemaphore(value: 0)
-        var synthesisError: Error?
-        XCTRunnerDaemonSession.shared().synthesize(event: record) { error in
-            synthesisError = error
-            semaphore.signal()
-        }
-        if semaphore.wait(timeout: .now() + 30) == .timedOut {
-            throw GestureError.synthesisTimeout
-        }
-        if let synthesisError = synthesisError {
-            throw GestureError.synthesisFailed("\(synthesisError)")
-        }
+        // Synchronous delivery: returns whether the event was synthesized and
+        // populates the error out-pointer on failure. This avoids the async
+        // completion-block path.
+        try record.synthesize()
     }
 }

companion/Sources/PrivateAutomation/PrivateAutomation.h

@@ -18,10 +18,13 @@ NS_ASSUME_NONNULL_BEGIN
 @end
 
 // A complete synthesized event composed of one or more pointer paths.
+// synthesizeWithError: delivers the event synchronously and returns whether it
+// succeeded, which avoids the asynchronous completion-block path.
 @interface XCSynthesizedEventRecord : NSObject
 - (instancetype)initWithName:(NSString *)name
          interfaceOrientation:(NSInteger)interfaceOrientation;
 - (void)addPointerEventPath:(XCPointerEventPath *)pointerEventPath;
+- (BOOL)synthesizeWithError:(NSError *_Nullable *_Nullable)error;
 @end
 
 // The runner-side session that delivers synthesized events to the system under