Migrate a v1 config to a v2 schema with an explicit mapping, and list what was dropped or defaulted
https://agents.writerslogic.com/api/v1/config-migrationOverview
Applies a declared mapping (from pointer, to pointer, optional transform such as string-to-number or a value map) to a v1 JSON config, carries over unmapped keys the v2 schema declares, fills schema defaults, validates the result against the v2 JSON Schema 2020-12 and returns the migrated config plus three exact lists: dropped (v1 values that landed nowhere, with their JSON pointers), defaulted (values invented from schema defaults) and invalid (v2 schema errors with paths).