openai/gpt-chat-latest → A (8:1)

Side A replaces synchronous vote handling with a dedicated settlement worker that batches event logging and ranking recomputation, introduces cached ranking reads (`ranked_items_cached`), warms the cache at startup, and switches UI rendering from write locks to read locks, while also removing the temporary demo-counter feature. Side B is a correct, targeted bug fix that skips stickied/pinned Reddit posts during subreddit import and adds a regression test, but its scope and architectural impact are much smaller.