Use monitor dimensions for default visualization size

Replace hardcoded 800x600 visualization size with actual monitor dimensions
from utils.get_monitor_dims() to ensure consistent scaling across different
display configurations.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: abrichr

openadapt/omnimcp.py

@@ -248,7 +248,9 @@ def visualize(self) -> Image.Image:
             Image: Annotated screenshot with bounding boxes
         """
         if not self.screenshot:
-            return Image.new('RGB', (800, 600), color='white')
+            # Get monitor dimensions instead of using hardcoded values
+            monitor_width, monitor_height = utils.get_monitor_dims()
+            return Image.new('RGB', (monitor_width, monitor_height), color='white')
 
         # Create a copy of the screenshot
         img = self.screenshot.copy()