Applied all fixes from critical review v3: - Issue 3.1: Added input validation to GetVersionIds - Issue 3.2: Removed redundant WriteLock in Rollback - Issue 3.3: Added audit entry for prior versions in DeleteVersion - Issue 3.4: Fixed Rollback return type (compilation fix) - Issue 3.6: Added clarifying comment for cancellation behavior 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>