Render full destination preview volume

docs/PORTING.md

@@ -132,8 +132,11 @@ square horizontal footprint with a vertical slice spanning 64 blocks below and
 63 blocks above the recorded linking location.
 
 Version 0.1.18 changes the preview cache to 9-by-64-by-9, spanning 32 blocks
-below and 31 above the link point. The Ponder section remains locked to the
-centered 9-by-7-by-9 window so the book retains a readable close-up.
+below and 31 above the link point. Its camera is centered on a 9-by-7-by-9
+window around the link point so the book retains a readable close-up.
+
+Version 0.1.19 renders the complete 9-by-64-by-9 snapshot in that Ponder
+scene while retaining the target-centered camera framing.
 
 The preview code is separated behind a renderer interface and uses an isolated
 Ponder level populated from server-authoritative destination snapshots.