fix: stop the duplicate scan from fetching every listed post

[Toldry]

Requested by Querent · project thread

Before: on v2.14.3, docker compose exec bot python -m racb --process-one crashed during the image duplicate scan with prawcore.exceptions.TooManyRequests: received 429 HTTP response. #89 made the scan read crosspost_parent_list and similar fields. Most listed posts don't have them, and when code reads a field a listed post lacks, PRAW downloads the whole post again. That was one request per post, up to about 1000 in a full scan.

After: the scan reads media fields only from what the listing already returned (duplicate_detector.post_attribute), so classifying listed posts makes no requests. A post known only by its id, like a comment's submission, is fetched once. Separately, a rate limit or network error while Phase 3 handles an entry no longer crashes --process-one or aborts the scheduled job with a traceback. It logs a warning, keeps the row for the next run, and stops the batch.

How: post_attribute reads vars(post) for PRAW objects. TRANSIENT_NETWORK_ERRORS moved from main.py to racb.core.reddit so Phase 3 can use it. phase3.handle_comment_or_defer wraps handle_comment. The new unit test builds real PRAW Submissions as a listing creates them, with _fetch patched to fail. It fails on master and passes here.

🤖 Generated with Claude Code

https://claude.ai/code/session_01PXeu2v7gGePkS9NhaCgwDy

---

Generated by Claude Code