The slipnet node previously called "bondFacet" was misleading since
"facet" is used throughout the codebase as a property name on Bond,
Group, and Rule objects. Renamed to "bond_edge_type" to better reflect
its role as a descriptor type category. Also removed precomputed
minPathToLetter data from slipnet.json.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>