Handle scalar TG extracted payloads

cmd/classifier/main.go

@@ -300,7 +300,12 @@ func (c *classifier) resolvePrompt(ctx context.Context, vertical, departmentID,
 func (c *classifier) saveVerdict(ctx context.Context, id int64, key string, verdict json.RawMessage) error {
 	_, err := c.db.Exec(ctx, `
 		UPDATE messages
-		SET extracted = jsonb_set(COALESCE(extracted, '{}'::jsonb), ARRAY[$2], $3::jsonb, true)
+		SET extracted = jsonb_set(
+			CASE WHEN jsonb_typeof(extracted) = 'object' THEN extracted ELSE '{}'::jsonb END,
+			ARRAY[$2],
+			$3::jsonb,
+			true
+		)
 		WHERE id = $1
 	`, id, key, string(verdict))
 	return err