Scan Age spawn columns from world top

README.md

@@ -37,8 +37,9 @@ Open a page-free Descriptive Book, name its Age, and press Create. Rivencraft
 assigns the book a permanent Age UUID, creates a dedicated vanilla-like runtime
 dimension, and prepares a five-by-five cobblestone arrival platform at the
 highest suitable nearby terrain. Solid blocks and tree leaves are valid
-footing. If no suitable surface is available, the
-platform is generated at Y=63. Reopen the book and click its preview to travel.
+footing. Candidate columns are scanned from the top down so cave floors are not
+selected, and fluid-covered columns are excluded. If no suitable surface is
+available, the platform is generated at Y=63. Reopen the book and click its preview to travel.
 Copies of the written book continue to resolve to the same persistent Age
 across server restarts.