Introduces agent-as-tool pattern infrastructure: - DelegationTask: Structured representation of expert work - DelegationResult: Typed result from expert delegation - delegate_to_librarian(): Wrapper for Librarian agent calls This implements PydanticAI's recommended delegation pattern where parent agents call child agents via tool wrappers. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>