another shutil update

bin/vcmp

@@ -203,20 +203,19 @@ def process_single_file(
     else:
         # File successfully converted to av1, move to destination
         target_path.parent.mkdir(parents=True, exist_ok=True)
+        success = False
+
         try:
-            shutil.move(str(temp_path), str(target_path))
-        except (PermissionError, OSError):
-            try:
-                logging.warning(f"Failed to move file with metadata, falling back to copy")
-                shutil.copy(str(temp_path), str(target_path))
+            # Use cp to copy file since it handles permissions better
+            subprocess.run(["cp", str(temp_path), str(target_path)], check=True)
             temp_path.unlink()
-            except Exception as e:
+            success = True
+        except subprocess.CalledProcessError as e:
             logging.error(f"Failed to copy file: {e}")
             if temp_path.exists():
                 temp_path.unlink()
-                release_file_lock(filepath)
-                return False
 
+        if success:
             logging.info(f"Successfully compressed {filepath}")
             if remove_source:
                 logging.info(f"Removing source file {filepath}")
@@ -224,6 +223,9 @@ def process_single_file(
             release_file_lock(filepath)
             return True
 
+        release_file_lock(filepath)
+        return False
+
 def process_directory(
         *,
         source_dir: pathlib.Path,