train: update extended schema, aliases, signals from gold tests

data/rag/index/kb_index.json

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:971db788d8c10a5f63b8ac7078597c32b3eb45debdba8de93e24097ecf7a81df
-size 65778731
+oid sha256:fec662dd49196192962ead4182cd82f1927d2e896b3296e30d4334c8afc7cf81
+size 91024369