Record source pilot boundaries and upstream decision

vision/first-party-source-plugins.md

@@ -12,6 +12,12 @@ source-specific image CDN allowlists and generic broker integration remain pendi
 MangaDex metadata, feed selection, catalog availability, and at-home page parsing
 now have a second opt-in worker path with fixture parity; its transport still
 uses the existing API client and runner.
+The MangaDex pilot deliberately retains the original in-process parser as a
+rollback path, so source-specific pure parsing is temporarily duplicated. Remove
+that duplication only after broader catalog fixture parity and a checkpoint-safe
+rollout. No Uchiyomi implementation has been copied: the reviewed Madara engine
+requires a challenge-solving fetch layer, and no third host has yet passed the
+access/permission and stable-interface gate for an archive adapter.
 
 ## Decision