feat: Add retry logic and fix thread termination in downloaders
- Implemented 5-attempt, 3-second countdown retry in
post_downloader.pyandcreator_downloader.pyfor robust downloads. - Resolved
ResourceWarninginpost_downloader.pywithwithstatements. - Fixed
RuntimeErrorincreator_downloader.pyby improving thread cleanup. - Enhanced
cancelmethods to stop retries instantly with safe thread termination. - Added translation keys for retry logging.
- Adjusted Max Simultaneous Downloads from 10 to 20