Add dev-prod harmonize tool for bidirectional catalog and image sync.

Schema migrates dev to prod only; catalog rows merge by updated_at and images by mtime with union merge and conflict reporting.

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

server/migrate.js

@@ -13,6 +13,7 @@ const INCREMENTAL_MIGRATIONS = [
   'migrate-portrait-thumbs.sql',
   'migrate-perf-indexes.sql',
   'migrate-search.sql',
+  'migrate-sync-timestamps.sql',
 ];
 
 async function bootstrapCurator() {