NanoClaw Host/Container Filesystem Boundary Vulnerability via Outbound Attachment Handling

NanoClaw version 1.2.0 and prior contains a host/container filesystem boundary vulnerability in outbound attachment handling and outbox cleanup that allows a compromised or prompt-injected container to read files outside the intended outbox directory by supplying crafted messages_out.id and content.files values or creating symlinked outbox files. Attackers can exploit this vulnerability to trigger host-side reads of arbitrary files and in some cases achieve recursive deletion of paths outside the intended cleanup target.