fix: remove unused nolint directive (CJK already escaped)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

pkg/agent/loop_media_test.go

@@ -178,7 +178,6 @@ func TestProcessPDFs_NilOCR(t *testing.T) {
 	}
 }
 
-//nolint:gosmopolitan // intentional CJK test data for Japanese reading order detection
 func TestDetectReadingOrder(t *testing.T) {
 	tests := []struct {
 		content    string