- Re-raise worker futures in as_completed to surface thread exceptions
- Replace hardcoded extension set with ALLOWED_EXT constant in compress_with_caesium
- Initialise work_dir/scratch_dir to None before try block to prevent NameError in finally
- Remove unused dead function get_slide_numbers_for_image
- Simplify redundant caesium_threads guard (threads and threads > 1 -> threads > 1)
- Write [Content_Types].xml first in ZIP to satisfy OOXML spec
Co-Authored-By: Abacus.AI CLI <agent@abacus.ai>
