fix: sync imgui fps to stream fps to avoid it interferes with displaylink timings

VoidLink/ImGuiRenderer.h

@@ -28,6 +28,7 @@ typedef void (^MetricsHandler)(int plotId, CFTimeInterval value);
 @property (nonatomic) BOOL enableGraphs;
 @property (nonatomic) float graphOpacity;
 @property (nonatomic) BOOL imguiRunning;
+@property (nonatomic) int streamFps;
 @property (nonatomic) MetricsHandler _Nonnull metricsHandler;
 
 -(nonnull instancetype) initWithFrame:(CGRect)bounds

VoidLink/ImGuiRenderer.mm

@@ -42,6 +42,9 @@
 
     _plots = [ImGuiPlots sharedInstance].plots;
 
+    // Store stream FPS to synchronize MTKView
+    _streamFps = streamFps;
+
     return self;
 }
 
@@ -90,7 +93,7 @@
 
     self.mtkView.device = self.device;
     self.mtkView.delegate = self;
-    self.mtkView.preferredFramesPerSecond = 60; // ImGui overlay will always render at this rate
+    self.mtkView.preferredFramesPerSecond = _streamFps; // Synchronize with stream framerate
     self.mtkView.opaque = NO;
     self.mtkView.enableSetNeedsDisplay = NO;
 
@@ -173,7 +176,7 @@
 #if TARGET_OS_SIMULATOR
     [commandBuffer presentDrawable:view.currentDrawable];
 #else
-    [commandBuffer presentDrawable:view.currentDrawable afterMinimumDuration:1.0 / view.preferredFramesPerSecond];
+    [commandBuffer presentDrawable:view.currentDrawable afterMinimumDuration:1.0 / _streamFps];
 #endif
     [commandBuffer commit];
 #endif