Fix video generation error: 'str' object has no attribute 'name'

Changed video_file.name to video_file since video_file is already a string path, not a file object.

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

Co-Authored-By: Claude <noreply@anthropic.com>

app.py

@@ -77,7 +77,7 @@ def generate_recammaster_video(
             
             # Copy uploaded video to temp directory
             input_video_path = os.path.join(temp_dir, "input.mp4")
-            shutil.copy(video_file.name, input_video_path)
+            shutil.copy(video_file, input_video_path)
             
             # Extract frames
             progress(0.2, desc="Extracting video frames...")