Expose sequence placement controls in the public API

records.go

@@ -189,14 +189,21 @@ type SourceInfo struct {
 	ID    string
 	Label string
 	Path  string
-	// Destination is the effective mapping path. Imports inherit their declaring
-	// document's path unless they append a YAML destination; overlay and CLI
-	// sources use the root path.
-	Destination   Path
-	Layer         Layer
-	Kind          SourceKind
-	UnderlayIndex int
-	ImportedFrom  *Location
+	// Destination is the effective mapping or sequence-container path. It is a
+	// detached snapshot. A fallback container is marked by DestinationUnresolved.
+	Destination Path
+	// PlacementMode describes how this source was placed. Mapping is the zero
+	// value; CLI and overlay sources report mapping placement unless item placement
+	// was applied to that source.
+	PlacementMode PlacementMode
+	// DestinationUnresolved marks Destination as the nearest resolved enclosing
+	// container when an enclosing item index is not yet assigned. It is false for
+	// exact destinations, including an item source's own sequence container.
+	DestinationUnresolved bool
+	Layer                 Layer
+	Kind                  SourceKind
+	UnderlayIndex         int
+	ImportedFrom          *Location
 	// VersionCheck is sanitized evidence for source-local declaration processing
 	// in an enabled source-version load. It is nil when that processing did not
 	// occur, including default mode and synthetic CLI sources. During callbacks