openai/gpt-chat-latest → A (3:2)

Side A fixes concrete failures in the test infrastructure by correcting query parsing (`str/split` regex), reading POST bodies from `getRequestBody`, handling null tokens/states safely, fixing redirect responses, and wrapping the mock OAuth handler to avoid crashes, restoring end-to-end authentication tests. Side B is primarily a UI simplification that removes the `ExpandNewThreadForm` action and server-renders the existing compose slot on the home page, which reduces code but is a design cleanup rather than a broad correctness fix.