Fix harmonize prod DB targeting and large-hall loading hangs.

Prod env files now win over root .env so harmonize:db can open gallery_prod after gallery_dev; tour_stops gains updated_at; halls no longer block the overlay on every painting texture. Docs cover the fixes and one-artist image pull from prod; Duccio painting assets synced from TrueNAS.

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

db/migrate-sync-timestamps.sql

@@ -21,9 +21,15 @@ BEGIN
     'paintings',
     'painting_influences',
     'painting_influence_sources',
-    'painting_annotations'
+    'painting_annotations',
+    'tour_stops'
   ]
   LOOP
+    -- Skip tables not created yet (e.g. tour_stops before migrate-tours.sql).
+    IF to_regclass(format('public.%I', tbl)) IS NULL THEN
+      CONTINUE;
+    END IF;
+
     EXECUTE format(
       'ALTER TABLE %I ADD COLUMN IF NOT EXISTS updated_at TIMESTAMPTZ NOT NULL DEFAULT now()',
       tbl