fix: update OCR result coordinates to center position

ai/compute.py

@@ -44,10 +44,8 @@ def perform_ocr(screenshot: bytes) -> list[dict]:
         if text and text.strip():
             results.append({
                 'text': text,
-                'left': data['left'][i],
-                'top': data['top'][i],
-                'width': data['width'][i],
-                'height': data['height'][i]
+                'x': data['width'][i] + data['left'][i] // 2,  # center x position
+                'y': data['height'][i] + data['top'][i] // 2  # center y position
             })
     return results