Prepare canonical party and derived players inputs

docs/internal/manifest.md

@@ -25,6 +25,12 @@ portable opaque segments. Unsafe legacy identities are rejected with migration
 guidance rather than being normalized into a different workspace or remote
 namespace.
 
+Prepare records independent `party` and `players` input checksums. In canonical
+party mode, the party record retains its campaign source identity while the
+players record uses `derived_from_party`; raw roster content is never embedded
+in manifest metadata. Both records remain the durable authority for consumers
+of their prepared input source IDs.
+
 The model admits these stage states:
 
 - `pending`