refactor(main.py): remove unused variables and improve mouse_callback method signature

main.py

@@ -39,7 +39,6 @@ class MediaGrader:
     CTRL_SEEK_MULTIPLIER = 10
     
     SEGMENT_COUNT = 16
-    SEGMENT_OVERLAP_PERCENT = 10
 
     def __init__(
         self, directory: str, seek_frames: int = 30, snap_to_iframe: bool = False
@@ -56,7 +55,6 @@ class MediaGrader:
 
         self.multi_segment_mode = False
         self.segment_count = self.SEGMENT_COUNT
-        self.segment_overlap_percent = self.SEGMENT_OVERLAP_PERCENT
         self.segment_caps = []
         self.segment_frames = []
         self.segment_positions = []
@@ -87,8 +85,6 @@ class MediaGrader:
         
         self.mouse_dragging = False
         self.timeline_rect = None
-        self.window_width = 800
-        self.window_height = 600
 
         self.undo_history = []
 
@@ -827,8 +823,6 @@ class MediaGrader:
             return
             
         height, width = frame.shape[:2]
-        self.window_height = height
-        self.window_width = width
         
         # Timeline background area
         timeline_y = height - self.TIMELINE_HEIGHT
@@ -859,7 +853,7 @@ class MediaGrader:
             cv2.circle(frame, (handle_x, handle_y), self.TIMELINE_HANDLE_SIZE // 2, self.TIMELINE_COLOR_HANDLE, -1)
             cv2.circle(frame, (handle_x, handle_y), self.TIMELINE_HANDLE_SIZE // 2, self.TIMELINE_COLOR_BORDER, 2)
 
-    def mouse_callback(self, event, x, y, flags, param):
+    def mouse_callback(self, event, x, y, _, __):
         """Handle mouse events for timeline interaction"""
         if not self.timeline_rect or not self.is_video(self.media_files[self.current_index]) or self.multi_segment_mode:
             return