openai/gpt-5.3-chat → A (3:1)

Commit A introduces a meaningful behavior change to the Reddit ingestion pipeline by filtering out pinned/stickied posts, adds a helper function, updates documentation, and includes a targeted test. This improves data quality and affects downstream processing. Commit B mainly removes a redundant guard and adjusts tests to reflect existing behavior, a smaller refactor with minor behavioral implications. Overall, A has broader functional impact.