openai/gpt-chat-latest → A (4:3)

Side A fixes a concrete data-import issue by filtering stickied/pinned Reddit posts during subreddit listing parsing, adds a dedicated helper, and includes a regression test covering both `stickied` and `pinned` flags. Side B simplifies the HTML/UI flow by removing the `ExpandNewThreadForm` action and server-rendering the compose slot on the home page, but it is primarily a refactor and UX consolidation rather than a functional correctness improvement.