NEXO Brain v7.30.7

Micro-release over v7.30.6 for Deep Sleep retention closeout.\n\n- Republishes the Deep Sleep retention/log-rotation update with the required release smoke artifact and contract in the tagged tree.\n- Keeps the same runtime behavior: bounded Deep Sleep DB backups, analyzed contexts, unfinished-context preservation, update-time cleanup, and log rotation.\n- Aligns public release surfaces, integration metadata, OpenClaw metadata, and release-readiness evidence for final closeout.

Full Changelog: v7.30.6...v7.30.7