openai/gpt-chat-latest → B (5:1)

Side B adds a substantial, functional `reddit.rs` implementation: a rate-limited Reddit API client, HTTP error handling, serde models for listings/posts/comments, custom deserializers, and helper methods for extracting typed data. Side A mostly introduces a planning document plus a thin `RouteContext` wrapper around `ThreadNav` that re-exports existing routing behavior, providing architectural direction but little immediate functional change.