Use Schema instead of Converting to Map

Much of the diff logic relies in converting the objects to maps. Investigate and implement a solution to use the Schema (when available) instead of converting to a generic map.

The issue does not name files or tests; start by locating the diff logic and the paths that convert objects to maps. Trace where Schema is available, then verify that those paths use it instead of generic maps while preserving existing diff behavior.

Written by the indexing model from the issue text.