The session existence checks in GET /stream and POST /messages were using options?.chatStore (global DB), so secondary-project sessions would throw notFound before the scoped ChatManager ran. Replaces with resolveScopedChatStore.
The session existence checks in GET /stream and POST /messages were using options?.chatStore (global DB), so secondary-project sessions would throw notFound before the scoped ChatManager ran. Replaces with resolveScopedChatStore.