openai/gpt-chat-latest → A (3:1)

Side A fixes a concrete import behavior by skipping Reddit stickied/pinned posts during subreddit listing parsing, adds a dedicated helper checking both `stickied` and `pinned` flags, and includes a focused regression test verifying only normal posts are imported. Side B mainly changes an optional lookup into an asserted invariant, updates indexing semantics/documentation, and adjusts tests and UI links, which is valuable for consistency but is a narrower refactor rather than a user-facing correctness fix.