Answer architecture round 3: New loads only sources without an index and what they read, an entry drops reads, ErrLoad sits beside New, the manifest decoder moves to manifest.go and names each mistake once as jsonvalue.Kind words it

CHANGELOG.md

@@ -128,5 +128,5 @@ replacement, and each removed path, column or flag.
 - A data source whose root holds a `.fejkdata.json` manifest with an `index` loads each
   category on the first call reaching it, as the shipped set does. Data failing to load,
   in `New` or there, gives an error matching `ErrLoad`, and the CLI exits 1. A source without
-  one loads in `New`, with the shipped categories it reads and every shipped category
-  depending on one it replaces; the rest of the shipped set still loads on first reach.
+  one loads in `New`, with the shipped categories it reads; the rest of the shipped set,
+  a reader of a category it replaces too, loads on first reach.