Implement a sanctioned session lifecycle for post-restart reconciliation so
active session rows with dead or reused owner PIDs can be terminalized
without deleting history. Protect live owners, live leases, and live
client-managed sessions; record durable session_retired audit events; keep
cleanup idempotent under concurrent reconciles.
Closes#969
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>