Checkpoints and recovery

The local CLI invocation is synchronous and writes its resulting .lsworld bundle only after discovery succeeds. It does not currently expose resumable optimizer checkpoints, a job queue, or server-side run recovery.

For long parameter sweeps, let an external workflow runner create one isolated output directory per immutable input/configuration pair. Write to a temporary filename, validate with lawsynth inspect, then atomically promote the bundle in the runner. Preserve stderr and the exact command for failed runs as well as successful ones.

Never resume by overwriting an existing accepted bundle. A distinct output path and content hash make it possible to distinguish a rerun from a changed configuration.