Remove auto-archival from hermes claw migrate — not its
responsibility (hermes claw cleanup is still there for that).
Skip MESSAGING_CWD when it points inside the OpenClaw source
directory, which was the actual root cause of agent confusion
after migration. Use Path.is_relative_to() for robust path
containment check.
Salvaged from PR #8192 by opriz.
Co-authored-by: opriz <opriz@users.noreply.github.com>