Verify ConfigKit integration and record release handoff

docs/internal/sources.md

@@ -49,6 +49,10 @@ Every configuration-loading command uses this boundary. The CLI maps only
 explicitly visited application flags to ConfigKit overrides and prints
 structured load diagnostics before engine construction. The old application
 YAML decoder and merge path have been removed.
+Application `config` inspection reuses the result's frozen effective,
+provenance, and history views without constructing an engine or reloading
+sources. It does not resolve API-key environment values; ordinary backend
+parameters remain visible by the selected inspection policy.
 
 ## Restricted HTTP Artifact Reader