Add guided tours and unify left-to-right hall wall hang.

Visitors walk published tours in a 3D hall with stop notes; curators edit drafts via Tour editor. All galleries (artist, movement, tour) place the first work left of the entrance view and the last on the right.

Co-authored-by: Cursor <cursoragent@cursor.com>

server/migrate.js

@@ -15,6 +15,7 @@ const INCREMENTAL_MIGRATIONS = [
   'migrate-search.sql',
   'migrate-sync-timestamps.sql',
   'migrate-i18n.sql',
+  'migrate-tours.sql',
 ];
 
 async function bootstrapCurator() {