revert: "fix: reject requests targeting a cachew playpen when not running as one (#204)"

This reverts commit 2f3c5c3.

Co-authored-by: Claude Code <noreply@anthropic.com>

Author: alecthomas

.bk.yaml

@@ -214,9 +214,6 @@ func newServer(ctx context.Context, muxHandler http.Handler, bind string, metric
 	)(handler)
 
 	handler = httputil.LoggingMiddleware(handler)
-	if os.Getenv("IS_PLAYPEN") != "true" {
-		handler = httputil.PlaypenGuardMiddleware(handler)
-	}
 
 	logger := logging.FromContext(ctx)
 	return &http.Server{