Remove legacy manifest provenance decoding

docs/operations.md

@@ -410,6 +410,30 @@ execute. Deleting Narratio's local reference snapshots does not invalidate a
 complete durable extraction; missing snapshots are reconstructed only when a
 later extraction actually runs.
 
+## Migrating Manifest Overlay Provenance
+
+The pipeline-selection rename is a clean cutover. Manifests containing
+`effective_config.selected_profile` are rejected by strict decoding; Narratio
+does not silently discard or translate that retired field.
+
+Before using an affected local session with the new version:
+
+1. Stop Narratio activity for the session and back up its manifest.
+2. Rename only `effective_config.selected_profile` to `selected_overlay`, keeping
+   its `name` and `source`, or remove the retired informational member. If a
+   current `selected_overlay` member already exists, retain it and remove the
+   retired member rather than creating duplicate keys.
+3. Preserve the schema version, digest, stage records, checkpoint evidence,
+   output references, and other session state. Retry the intended command.
+
+This metadata is informational, not resume authority. Do not delete session
+progress or force all stages merely to perform this migration. Other unknown
+fields still require investigation rather than blanket removal.
+
+Do not edit immutable remote committed snapshots. Restoring an older snapshot
+with retired provenance requires a compatible previous Narratio version, followed
+by migration of the restored local manifest before using the new version.
+
 ## Migrating Audita and Provider Credentials
 
 This is a breaking clean cutover to Audita v2. Narratio does not translate an