Define identified configuration resources

docs/roadmap/implementation.md

@@ -243,6 +243,14 @@ Validation: inspect the registration selectors and schema; when runnable, load
 one headerless root list and one version-2 collection. Resolution/validation
 callers are completed in the following stages.
 
+Completion: the typed document now uses identified resource slices, registers
+all six root and collection identity rules, and checks specification version 2.
+Added a focused root/collection list fixture and reviewed the selectors and
+schema. The focused test cannot yet compile because field capture, resolution,
+validation, indexing, prompt materialization, and older fixtures still expect
+maps; those migrations are assigned to the following stages. Formatting and
+`git diff --check` passed; execution of the new fixture remains deferred.
+
 ## Stage 4: Preserve Field Presence And Resolution At List Paths
 
 Scope: backend/profile field capture, normalization, and defaulting in