Photo deduplication is cheaper and shows live progress

Text-only deduplication cuts costs by 64% with live progress visibility.

Improvements

Photo deduplication now uses text-only analysis instead of vision-based analysis, reducing costs by 64% while maintaining quality. The process runs in parallel with per-chunk retry isolation, so problematic photos don't delay the entire batch. A real-time progress bar now displays deduplication status instead of spinning indefinitely.