openai/gpt-chat-latest → B (9:1)

Side B introduces substantial lasting infrastructure: it adds a new RocksDB-backed `durable` workspace crate, moves raw Reddit entity payloads out of in-memory state into a persistent `EntityStore`, and changes event-log replay to stream entries one at a time, reducing startup memory while preserving replay semantics with new tests. Side A is a correct, targeted bug fix that skips stickied/pinned Reddit posts during subreddit import and adds a regression test, but its scope and long-term impact are much smaller than the storage and replay architecture changes in Side B.