Pass hierarchy or connection identity from the producing call rather than
searching graph IDs containing caller-selected paths and authored IDs. Keep
connection omissions from making a retained hierarchy appear partial.
Replace mirrored ID-substring test oracles with exact endpoint relationships.
Cover marker-bearing paths and authored identities through domain, CLI/MCP,
summary and byte-retention boundaries.
Validation: affected source and compiled/public tests passed, including native
Foundation/ibtool fixture lanes; one Linux-only invalid-byte filename case
skipped on macOS. Static, docs and discovery checks passed.