fix:docker build failed without these changes

[hschinmayabharadwaj]

Main Problems Fixed:

1. Uncontrolled Concurrency - Added IMAGE_TOOL_BATCH_SIZE = 20 to prevent API rate limits
   when processing many images simultaneously
2. Incorrect Semantics - Changed from applying one prompt to multiple images (edit_image)
   to independent edits with their own prompts (edit_images). This ensures each image gets
   appropriate instructions.
3. Result Ordering - Implemented explicit order preservation so results match input order,
   fixing frontend display issues
4. Poor Error Handling - One failed image no longer breaks the entire batch. Errors are
   caught individually and processing continues
5. Local Asset Support - Automatic conversion of local asset URLs to data URLs for
   providers that can't access localhost

Technical Changes:

• remove_background() → remove_backgrounds() with batching
• edit_image() → edit_images() with restructured schema (array of edits)
• Renamed core functions to remove_background_once() and edit_image_once()
• Updated frontend to display parallel operations correctly
• Added comprehensive batching tests