Adopt ConfigKit for pipeline loading

examples/production-testing/pipeline.yml

@@ -1,15 +1,9 @@
 # Copyable production/testing pipeline entry point. Every fragment is named
 # explicitly; Narratio never scans conf.d automatically.
-composition:
+configkit:
   imports:
-    - conf.d/platform.yml
-    - conf.d/storage.yml
-    - conf.d/transcript.yml
-    - conf.d/artifacts.yml
-    - conf.d/publish.yml
-  default_profile: production
-  profiles:
-    production:
-      overlay: profiles/production.yml
-    testing:
-      overlay: profiles/testing.yml
+    - path: conf.d/platform.yml
+    - path: conf.d/storage.yml
+    - path: conf.d/transcript.yml
+    - path: conf.d/artifacts.yml
+    - path: conf.d/publish.yml