fix(main.py): conditionally display info overlay and timeline for video files only

main.py

@@ -167,6 +167,7 @@ class MediaGrader:
 
         # Add info overlay
         current_file = self.media_files[self.current_index]
+        if self.is_video(self.media_files[self.current_index]):
             info_text = f"Speed: {self.playback_speed:.1f}x | Frame: {self.current_frame}/{self.total_frames} | File: {self.current_index + 1}/{len(self.media_files)} | {'Playing' if self.is_playing else 'PAUSED'}"
 
             cv2.putText(
@@ -189,6 +190,10 @@ class MediaGrader:
 
     def draw_timeline(self, frame):
         """Draw timeline at the bottom of the frame"""
+        # Only draw timeline for video files
+        if not self.is_video(self.media_files[self.current_index]):
+            return
+            
         height, width = frame.shape[:2]
         self.window_height = height
         self.window_width = width
@@ -210,7 +215,7 @@ class MediaGrader:
         cv2.rectangle(frame, (bar_x_start, bar_y), (bar_x_end, bar_y + self.TIMELINE_BAR_HEIGHT), self.TIMELINE_COLOR_BORDER, 1)
         
         # Draw progress for videos
-        if self.is_video(self.media_files[self.current_index]) and self.total_frames > 0:
+        if self.total_frames > 0:
             progress = self.current_frame / max(1, self.total_frames - 1)
             progress_width = int(bar_width * progress)
             if progress_width > 0: