Filters issues by parent issue ID using parent-child dependencies. Example: bd list --parent=bd-xyz --status=open Changes: - Add ParentID field to IssueFilter type - Add --parent flag to list command - Forward parent filter through RPC - Implement filtering in SQLite and memory storage 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>