openai/gpt-chat-latest → B (10:1)

Side B makes a substantive architectural change: it removes persistent storage of Reddit API payloads and the `EntityImported` event, replaces them with ephemeral projection-cached display content plus TTL eviction, updates replay/journaling/projection logic accordingly, and adds tests reflecting the new persistence model. Side A primarily adds a planning document and introduces a thin `RouteContext` wrapper re-export without migrating callers or changing runtime behavior, so its lasting project impact is much smaller.