Add "format": "full" option to memory_query that renders with
full content, graph metrics, and hub analysis (format_nodes_section).
Convert 6 agents (linker, challenger, connector, extractor, replay,
transfer) to inline their queries via {{tool: memory_query}} instead
of separate header query + {{nodes}} placeholder.
Co-Authored-By: Proof of Concept <poc@bcachefs.org>