fix: store refresh-at as string type, not date type, for sqlx autotyping

Taskfile

@@ -12,7 +12,8 @@ refresh_sqlx_db() {
   rm -f some_user.db
   for migration in migrations/each_user/*.sql; do
     echo "Applying $migration..."
-    sqlite3 some_user.db < "$migration"
+    echo "BEGIN TRANSACTION;$(cat "$migration");COMMIT TRANSACTION;"\
+      | sqlite3 some_user.db
   done
 }